Csr Limited Trading As the Readymix Group v ACT Land Developments Pty Limited; Ross Joseph Lentini and Dominic Anthony Lentini [1990] ACTSC 44 (13 November 1990)

SUPREME COURT OF THE ACT

CSR LIMITED TRADING as THE READYMIX GROUP v. ACT LAND DEVELOPMENTS PTY.
LIMITED; ROSS JOSEPH LENTINI and DOMINIC ANTHONY LENTINI
S.C. No. 3 of 1988
Contract

COURT

IN THE SUPREME COURT OF THE AUSTRALIAN CAPITAL TERRITORY
Miles C.J.(1)

CATCHWORDS

Contract - agreement to provide concrete over period of time - question of single continuing contract or series of discrete contracts.

Contract - sale of goods - question as to whether goods were of merchantable quality or reasonably fit for purpose made known.

HEARING

CANBERRA
13:11:1990

Counsel for the plaintiff: Mr P. Biscoe

Solicitors for the plaintiff: Gallens Crowley and Chamberlain

Counsel for the defendants: Mr P.W. Neil and Mr Wright

Solicitors for the defendants: Pamela Coward and Associates

ORDER

The parties be given leave to bring in short minutes within seven days.

The matter be adjourned to a date to be fixed.

DECISION

The written submissions on behalf of the plaintiff commence with the statement that "this is a sale of goods case". So it is, and more. The plaintiff sold and delivered premixed or "readymix" concrete to the first defendant. The concrete when placed cracked badly. The plaintiff says that the fault was in the way the concrete was placed by the first defendant. The first defendant says that the fault was in the concrete as delivered. The first defendant has not paid for the concrete (except for a small sum). The other defendants guaranteed the payment by the first defendant. The other defendants play no active part in the case and from now on the first defendant will be referred to simply as "the defendant".

2. There was a lot of technical and expert evidence in the case. Some of the primary facts were not in issue, but others are central to a resolution of the dispute. Some of the primary facts in issue cannot be resolved without a consideration of the technical and expert evidence, but the primary facts need to be resolved before other parts of the technical and expert evidence can be applied to them.
1. Pleadings

3. The plaintiff relies upon an agreement between the plaintiff and the defendant that the plaintiff would sell and deliver goods to the first defendant on credit for payment after delivery. The plaintiff further alleges that in accordance with that agreement and at the request of the first defendant the plaintiff duly sold and delivered goods to the defendant. The defendant admits that there was an agreement relating to the price of concrete to be delivered, but that each delivery of concrete constituted a separate agreement between the parties. The defendant further alleges that it was an implied condition, alternatively an implied warranty, in each of these separate agreements that the concrete delivered would be of merchantable quality and that it be reasonably fit for the purpose for which it was required, namely slabs on which heavy trucks would be driven and parked. The defendant also alleges that there was an implied warranty in each of the agreements that the plaintiff would exercise due care and skill in the mixing and delivery of the concrete. The plaintiff admits that these were contractual terms but denies breach. An allegation by the defendant of a total failure of consideration was abandoned at the hearing.

4. A further matter raised by the defendant both by way of defence and in counterclaim is an allegation that there was an express or implied term that the concrete would have an adequate quantity of 20 mm aggregate, maximum 80 mm slump, and SAA type A Portland cement. The defendant further alleges breach in that the concrete "contained about ten percent too little 20 mm aggregate, about 85 mm to 130 slump and cement containing about 35 percent too much slag by weight of cementitious material (or binder)". The plaintiff denies that there was such a term and condition and denies the alleged breach.
2. Concrete

5. As the case is all about concrete, it is as well to begin by saying something about the characterists of concrete as established by the evidence.

6. Concrete consists of a dry mix of coarse aggregate, fine aggregate (sand) and a cementitious binder (cement) to which water is added. The cement reacts chemically to the water (the hydration process) and at the same time the particles of aggregate settle down by gravity so that a film of free water forms at the surface. If the particles of aggregate and cement and the amount of water are all in proper proportions, there is a minimum of space between the particles. If a proper proportion of water is added there will be only a thin film of free water at the surface. In the first couple of hours after placement the hydration process occurs and the mass of concrete is in a plastic state. As the water evaporates from the interior of the concrete via the surface, the mass begins to shrink. The concrete achieves relative hardness and stability within a period of some days during the "curing" period. After that it nevertheless continues to contain moisture but will dry out slowly and continue to shrink slightly over a long period, possibly years, during which it continues to gain strength.

7. The greater the amount of water used in the mix, the more likely that cracks will form in the concrete because of the greater space between the solid particles and the greater tendency to shrinkage during and after evaporation. The greater the amount of sand proportionate to coarse aggregate, the greater the amount of water necessary to make the mix workable, and, because of the greater amount of water present, the more likely that shrinkage and cracking will follow. Hence, generally speaking, and despite some disagreement in the expert evidence about exactly why it happens, an "over-sanded" mix will be more prone to crack.

8. Concrete used for paving internal areas is usually poured on to a base lined with plastic sheeting. Concrete used for paving external areas may be poured on to a base lined with plastic sheeting or on to a base of bare earth or sand properly dampened down.

9. Steel reinforcing mesh is used in concrete paving. Sheets of mesh are cut to size and placed in the base prior to pouring of the concrete. The mesh is placed on small plastic or metal "chairs" (shaped like stools) which keep the mesh free of and above sub-base and entirely within the concrete slab.

10. Some degree of cracking in concrete paving is inevitable and acceptable in the construction industry. There are three types of cracking.

11. Settlement cracking can occur in the first hour or two after pouring. It is generally due to the concrete attempting to settle down over extraordinarily large pieces of aggregate or over the reinforcing steel. Settlement cracking can usually be overcome by proper finishing techniques, particularly the use of a concrete vibrator which has the effect of packing the concrete down over the obstruction and sealing the cracks. Settlement cracks are not usually serious but may provide "planes of weakness" for the location of other later cracking.

12. Plastic shrinkage cracking occurs during the first few hours after placement and after initial hardening of the surface but whilst the concrete mass is still in its plastic state. There are two views about why it occurs. One is urged on behalf of the plaintiff, namely that plastic shrinkage cracking occurs when the rate of evaporation at the surface exceeds the rate of migration or diffusion to the surface of water within the concrete. This sets up stresses in the mass between areas of different moisture content and different degrees of hardness and strength which stresses resolve in cracking. The other view, and that which is urged on behalf of the defendant, is that when excess water has been added to the mix, it leads to pressure within the concrete which cannot be contained within the concrete and which results in cracking where there is least resistance, namely at the surface.

13. Drying shrinkage cracking (or restraint cracking) occurs after a period of days has elapsed from the time of pouring. It is caused by the concrete mass as it dries tending to shrink across the sub-base but being unable to do so freely because of some external restraint. Again, the resolution of the opposing forces is in the cracking of the concrete. A common cause of drying shrinkage cracking is an uneven sub-base surface. On the other hand, concrete laid on a base of plastic sheeting is less liable to suffer from drying shrinkage cracking than concrete laid on an earthen base because it is subject to less restraint as it attempts to slide or shrink across the sub-base. Large areas of concrete which are not provided with expansion joints at the perimeter are also subject to drying shrinkage cracking.

14. Curing is a term of apparent imprecise content. The curing of concrete commences after the concrete has reached the initial stage of hardening at the point where it can be walked on without damage to it. Effective curing is achieved by keeping the surface moist, for example, by covering with hessian and watering down, or covering with plastic after or without watering down, or applying a chemical curing agent.

15. The cement used in concrete is of different types. A common type in Australia is Portland cement, manufactured from crushed and processed limestone. A high quality cement in common use in Australia is Type A Portland cement. Another type of cement is manufactured and sold under the name of slagment. Slagment consists of 65 percent Type A Portland cement and 35 percent crushed industrial slag. The slag used in slagment is reactive to water in the same sort of way as Type A Portland cement but it is not reactive to the same degree. In the first two or three days after placement, concrete made up from a mix including slagment will contain more free water than concrete made up from a Type A Portland cement only. After some time concrete containing slagment will develop as much if not more strength than the Type A concrete.

16. One test that may be used to give an indication of the workability of, and the amount of water in concrete is the slump test. A sample of a given quantity of the concrete is placed in a cone shaped container and the container is removed. A measurement is then taken of the slump, that is the vertical distance by which the mass subsides. Where a particular slump is specified, a tolerance of 15 mm either way is regarded in the industry as acceptable.
Background

17. The plaintiff was in business as a supplier of readymix concrete to the construction industry from its batching plant at Fyshwick. The defendant was the concreting sub-contractor in the construction of a warehouse at Nyrang Street, Fyshwick more particularly the internal floor and external paved areas. The head contractor was Atlantic Civil Pty. Ltd. (Atlantic Civil). The proprietor was F and R Iannelli and Sons Pty. Ltd. (Iannelli). The defendant had the task of supplying all material concerned with preparation of the site for placement of the concrete and of supplying, pouring and finishing of the concrete.

18. On 6 August 1986 Mr Ross Lentini, a director of the defendant, signed and completed a credit account application form for the granting of credit by the plaintiff. The application form included a clause stating "that the granting of credit will imply a Contract entered into by the Applicant/s and CSR LIMITED in accordance with the standard conditions of sale and delivery". These latter conditions were contained in a document entitled "Terms and Conditions of Sale - Concrete". A copy was supplied by the plaintiff to the defendant in August 1986. Clause 7 of those terms provides:
"Where an order is based on a quotation and is made:

(a) orally, each load of product delivered shall
form a separate and distinct contract which
shall be subject to the terms and conditions
of the quotation and to these terms and
conditions;
(b) ....."

19. Clause 2 of the Terms and Conditions of Sale states that "placement of an order, either orally or in writing, implies acceptance of these terms and conditions".

20. Other relevant clauses for the purposes of the case are as follows:
"18. All concrete is offered for sale under

Australian Standard Specification AS1379, unless
otherwise stated on the face of the delivery docket.
The concrete supplied is as detailed on the delivery
docket, the seller is
unable to accept responsibility in respect of
strength or any defect which may develop in any
concrete supplied if:
(a) water is added to concrete either before or
after discharge from the delivery unit without
the sanction of the seller's representative;
(b) an admixture is used in the concrete at the
buyer's request or specification;
(c) such lack of strength or defect is due to
faulty handling, placing or curing by the
buyer; or
(d) such lack of strength or defect is due to
faulty or defective job practice by the buyer.
.....
22. Unless otherwise stated in the quotation,
prices for concrete are based upon slumps not
exceeding 80 mm using 20 mm maximum size aggregate.
Slumps in excess of 80 mm and maximum size aggregate
below 20 mm are subject to an extra charge at the
seller's ruling rate at that time.
.....
24. Concrete supplied for pumping may be subject
to a surcharge and the buyer must inform the seller
when this type of concrete is required."

21. Australian Standard Specifications AS1379-1973 provides in paragraph 2.2.1 (exhibit K) that unless otherwise specified, the cement shall be Type A in accordance with the requirement of AS1315, or Type FA or Type SA as defined in AS1317. It is common ground that Type SA is slag cement, which includes the commercial product known as "slagment". Otherwise there is no evidence of the requirments of AS 1317.

22. Between August 1986 and November 1987 the plaintiff supplied quantities of concrete to the defendant at various sites in the Canberra district in accordance with the contractual arrangements between them. The present case, however, is concerned only with the contract or contracts relating to concrete delivered between 10 October and 13 November 1987.

23. In August 1987 Mr Ross Lentini spoke on the telephone to Mr Keith Dryden, sales representative employed by the plaintiff, requesting a quotation for 1,000 cubic metres of concrete of 20 mpa strength. On 6 August 1987 the plaintiff forwarded to the defendant a quotation for the supply of 1,000 cubic metres of concrete of 20 mpa strength at a price of $101 per cubic metre. There was a subsequent telephone conversation between the two men relating to price and Mr Lentini agreed on 25 August to lower the price to $100.50 per cubic metre. On or about 12 October 1987 Mr Ross Lentini asked that the strength of the concrete to be supplied be increased to 25 mpa and it was agreed between the two men that the price would be increased to $104 per cubic metre and that the strength of the concrete supplied would be increased to 25 mpa. During the course of these conversations Mr Dryden became aware that the purpose of the concrete was for paving the interior of the Iannelli warehouse which was in the course of construction and of the driveway and adjacent areas and that the paving would in due course be subject to heavy vehicular traffic.

24. Work then proceeded on the area of the base (in evidence sometimes referred to as the "sub-base") upon which the concrete slab was to lie. This work (or some of it) was carried out by the defendant under the supervision of Mr John Bailey on behalf of Iannelli. In passing it may be noted that the defendant as sub-contractor to Atlantic Civil was responsible not to Iannelli but to Atlantic Civil, and that another sub-contractor, Mr Frank Barbaro, or a company associated with him did some work on the sub-base.

25. By 18 October 1987 the sub-base was prepared to the extent that it remained only for the defendant to pour the slab. It was necessary to place the specific orders for delivery of concrete. The procedure that the defendant followed for such specific orders was that on the day prior to each of the days on which it was proposed that concrete be delivered Mr Ross Lentini rang the plaintiff's batching plant and spoke to someone whom he understood to be a despatcher. He then ordered concrete by stating the quantity he wanted delivered, the time of delivery and the strength. According to that procedure deliveries of concrete were made by the plaintiff to the site at Nyrang Street, Fyshwick, between 19 October and 13 November 1987. The concrete in every delivery was made up from one or other of two batch mixes which, within the plaintiff's organization, were identified as 270/702 and 285/604 respectively. Some details (which appear from delivery dockets Exhibit N and AB1, AB2 and AB3) of the deliveries are as follows:

Date No. M3 Per Total Batch Location
Loads Load M3 Mix
October
19 11 5 270/702 internal
1 3 58
20 15 5 270/702 internal
1 3 78
21 15 5 75 270/702 internal
22 14 5
1 1 71 270/702 internal
23 14 5
1 3 73 270/702 internal
29 18 5
1 3.2 93.2 285/604 internal
30 20 5 100 285/604 internal
November
6 24 5
1 2 122 285/604 external Note 1
9 12 5 60 285/604 external
11 8 5 285/604 external
6 5 70 285/604 internal
12 1 5
2 4.4
2 4.6 23 285/604 external
13 8 5
1 2.4 42.4 285/604 external

Note (1): There are discrepancies in the records which cannot

be resolved. There may have been only 23 deliveries
of loads of 5 m3, in which case the total would have
been 117 m3.

26. It is the case for the defendant that on the occasion of the first order on 18 October 1987 Mr Bailey as well as Mr Lentini spoke to the plaintiff's despatcher and that Mr Bailey specified that Type A cement was required. This is denied by the plaintiff.

27. During the pouring of the concrete in the internal bays of the warehouse, the concreters experienced difficulty with the unusually long time taken for the concrete to dry sufficiently for the finishing work to be carried out to the surface. There was also an unusually high amount of "bleed water" appearing on the surface of the internal slabs. The internal bays were subjected by the defendant to treatment with a hardening and curing compound called "ashford formula", which was applied to the surface of the slab the morning after the day of the particular pour. The procedure adopted for the pouring of the internal part of the slab was that in general in the earlier stages individual bays of the slab were poured direct from the delivery truck, and in the later stages the concrete had to be pumped from the truck because of difficulty of access for the truck.

28. The procedure adopted by the plaintiff for the making up and delivery of the concrete was as follows. For each delivery, the despatcher, by reference to a batch card, deposited the requisite quantity by weight of each of the ingredients of the mix into a hopper. The contents of the hopper were then placed into the barrel of the mixer on the delivery truck and a certain quantity of water was added by the despatcher. It then became the responsibility of the truck driver to ensure that the concrete was properly mixed by the time of arrival and delivery at the site.

29. Each of the plaintiff's batch cards set out the required quantities by weight of the various ingredients which went to make up each of the plaintiff's "off the shelf" mixes. Up to and including 30 October 1987 all concrete went into the internal bays and the concrete delivered was made up substantially as the mix prescribed in batch card 270/702, with this difference. Whereas mix 270/702 prescribed certain quantities of Type A Portland cement, what in fact went into the mix delivered to the defendant was slagment. The concrete delivered after 23 October 1987 was, except for all deliveries on 29 and 30 October and six deliveries on 11 November, for the external slab. The concrete poured for the external slab was all prepared according to the mix set out in batch card 285/604, a mix for which slagment and not Type A cement was a prescribed ingredient. Most of the concrete supplied for the internal work was made up from mix 270/702. On the three last days of the internal work the mix used was mix 285/604.
4. Internal Pours

30. Pouring of the internal slab took place on several days in the period beginning 19 October and finishing 30 October 1987 (except for a final pour on 11 November). The required depth of the concrete in the internal area was 125 mm. The concrete was poured into bays defined by formwork. Generally, it was not practicable to pour into an adjacent bay until the adjoining concrete had hardened to some extent, at least overnight. Hence internal bays were poured alternately, and once several alternate bays had been poured, access for the delivery trucks became difficult, necessitating pumping the concrete from the mixer. The external paving was not divided up into bays in the same way. One continuous section of the external slab was placed on each day of pouring and the practice was followed of making cuts or saw cut joints part way into the poured section of the slab, usually on the following morning. This was in accordance with usual industry practice. Plastic sheeting was used to line the sub-base for the internal concrete but not the external concrete.

31. When the internal concrete (of required depth of 125 mm) abutted against walls, pillars and other structures, a bituminous felt ("jointex") was used to separate the structure from the concrete and to form what was called an expansion joint. Jointex was also used where the external concrete abutted the exterior walls of the building. The jointex used was 100 mm wide. It was not wide enough to completely penetrate the slab either inside or outside the building. The concrete outside was 150 mm in depth. It is not in dispute that the slab was in contact with the structures.

32. Whilst the pouring of the internal section of the bays was taking place the concreters had trouble finishing the edges of some of the bays because of unusual softness of the concrete. Within a week or so of the pouring of the internal bays some minor cracking was noticed but was not regarded as unusual. Over time more cracking has been observed, particularly in areas adjacent to columns and doorways. The cracks have been observed to widen and will become such that a substantial proportion of the internal paving will have to be removed and the area repaved.
5. External Pours

33. The pouring of the external section of the slab commenced on 6 November 1987. The first area outside the building which was poured was the northern part of the driveway. The pour arranged for that day was by far the biggest pour arranged at that stage and, as it turned out, for the whole of the concreting work on the project. Mr Lentini said that he arranged for the delivery trucks to arrive at ten minute intervals. The pour commenced between 6 and 6.30 a.m. Twenty-four truckloads of 5 cubic metres of concrete each had been deposited by 9.15 a.m. and a final load of 3 cubic metres was deposited at 10.35 a.m. The finishing work to the surface of the concrete was completed by about 2 p.m. at which stage all the concreters went to a local tavern for lunch. Whether any and what steps had been taken to cure the poured concrete at that stage is in dispute. The defendant's case is that all proper steps for curing including hosing down were taken before 2 p.m. and that at about 4 p.m. Mr Frank Barbaro covered the concrete with plastic and hessian. It is also the defendant's case that local rain in the area fell during the afternoon, which had the effect of keeping the surface of the concrete damp. That also is in dispute.

34. Mr Barbaro returned to the site the following morning at which stage he noticed numerous fine cracks in the surface of the concrete. Other people who came or were summoned to the site noticed the same thing. According to the defendant's case, the concrete was then hosed down again, the hessian and plastic replaced and kept in position for about a week. Work on the remainder of the northern part of the driveway continued over four days of the following week, but at a much slower pace with a view to avoiding the problems that had been experienced with the concrete poured on 6 November. Otherwise, according to the defendant's case, the same placing and curing techniques were used. The same cracking problems were experienced in relation to the external work carried out after 6 November. Concrete placed in the interior of the warehouse on 11 November did not result in cracking of unusual or unacceptable severity.

35. With the repeated problems in the cracking of the external concrete, the defendant ceased to order readymix supplies from the plaintiff. An alternative source of readymix concrete was found and used to complete the external slab. Although the concrete from the alternative source, referred to in evidence as the BMG concrete, resulted in minor cracking, that was not regarded as unusual or unacceptable.

36. The cracking in the external slab comprised by the concrete supplied by the plaintiff has widened over a period of time. The cracking in the internal slabs in the warehouse also has been observed to have grown worse and further cracking has appeared in parts of the external concrete where it abuts the warehouse itself and other structures.
6. Was Type A cement specified?

37. The defendant contends as one of its arguments that it was an express term of the agreement that the concrete supplied would be of a mix containing Type A cement and no other type of cement. Evidence was given by Mr Ross Lentini and Mr Bailey of a telephone conversation between Mr Lentini and someone at the Readymix plant on 18 October 1987 in which Mr Lentini ordered a quantity of concrete to be delivered the following day. Both witnesses also said that Mr Bailey as well as Mr Lentini spoke on the telephone on that occasion and that Mr Bailey specified that Type A cement should be used in the mix. Mr Bailey, it will be remembered, was engaged as a supervisor by the proprietor Iannelli and not by the plaintiff and not by the head contractor, Atlantic Civil. His role in the contractual arrangements between the defendant (the sub-contractor) and the plaintiff (the supplier to the sub-contractor) is, on any view, an unusual one. He said in evidence that it was his practice always to specify Type A concrete. He said that he spoke to the Readymix despatcher in order to read out the engineering specification on the plans. Yet the plans contain no reference to Type A cement or indeed to any type of cement. He did not know the name of the despatcher. Other evidence which I accept established that there were in fact two despatchers employed at the time at the Readymix plant. One was Mr Allan Vest, who gave evidence. The other one, who was not identified by name, had left the plaintiff's employ at the time of the hearing and could not be traced. Mr Vest said in his evidence that he could not remember anyone ever specifying Type A cement when placing an order. Indeed it would seem that if an order for delivery was based on a prior quotation, as contemplated by Clause 7 of the Readymix Terms and Conditions of Sale, then the specification at a later date of the type of cement would be either superfluous or a variation of the quotation, unless the quotation was silent on the contents of the mix or the type of cement to be used in the mix. The quotation in this case was of course silent on both those matters. In any event, I am satisfied that the specification by the customer of the type of cement to be used in the concrete to be supplied was not a common occurrence. Mr Vest also said in his evidence that he took his daily instructions on what to make up for despatch from another employee of the plaintiff, the shipper, Mr Colin Paulus. Mr Paulus was not called to give evidence, there was no explanation for his absence and there was no evidence of what the shipper's function was. Although I accept the evidence of Mr Vest and although there are some unsatisfactory aspects about the defendant's case relating to the telephone call, I do not think that it is shrouded in sufficient doubt to justify the rejection of the evidence of Mr Bailey and Mr Ross Lentini that the phone call of 18 October in fact took place and that there was a conversation along the lines they indicated. An order was clearly placed on that day, because the concrete was in fact despatched the following day. Someone on the part of the plaintiff (not Mr Vest) accepted the order and had ostensible authority to do so. In my view, that person also had ostensible authority in accepting the order to do so on the understanding, as specified on behalf of the customer, that the cement in the concrete to be supplied would be of Type A Portland cement. On the probabilities I find that there was a telephone conversation between Mr Bailey and an authorised representative of the plaintiff on 18 October 1987 in which it was agreed that the plaintiff would supply a certain quantity of concrete to the defendant the following day which concrete was to contain Type A Portland cement and no other cementitious binder. However, the evidence about the telephone call is not sufficiently clear or persuasive to satisfy me that anything was said that made it a term and condition that deliveries pursuant to the quotation dated 6 August 1987 to be made after 19 October 1987 were to be of Type A Portland cement.

38. One further point needs to be made here. Slagment is a mixture of 65 percent Type A Portland cement and 35 percent crushed slag. It does not consist entirely of slag. Hence the supply of concrete containing slagment was not of concrete entirely lacking in Type A Portland cement. Concrete containing slagment has simply a reduced proportion and not an absence of Type A Portland cement. Nevertheless, it is not, in my view, an answer to the defendant's complaint that Type A was specified and not supplied to say that slagment contains a proportion of Type A. In specifying Type A cement, Mr Bailey was, in my view, to be taken to be specifying that Type A and no other cementitious binder was to be used in the mix to be supplied in accordance with the phone call. On that basis the order was accepted on behalf of the plaintiff. I find that it was an express term of the contract that the concrete to be supplied in accordance with that order was to be of a mix containing Type A Portland cement and no other cementitious binder and hence the supply on 19 October of concrete in which the cementitious binder was slagment and not Type A Portland cement was in breach of that express term. However, there was never any repetition of the specification of Type A. The evidence is silent about what was said when subsequent orders for deliveries on subsequent days were placed. On the defendant's case every order placed and accepted constituted a new contract although based on the same quotation, a quotation which made no reference at all to the ingredients in the mix. Hence, I conclude that in relation to all orders placed after 18 October 1987 there was no term express or implied that Type A Portland cement would be used in the mix. The relevant term in this regard was, in my view, the term implied by s.19(2) of the Sale of Goods Act 1954, that is to say, that the concrete was reasonably fit for the purpose for which it was supplied, namely paving for the carrying of heavy vehicular traffic.

39. The defendant's success on this issue is something of a hollow victory because for reasons which will appear later it has not been shown that the substitution of slagment for Type A in the concrete supplied on 19 October or the supply of concrete containing slagment on that or any other day resulted of itself in any damage. To put it another way, it has not been shown that whatever damage was sustained would have been avoided by the use of Type A Portland cement rather than slagment.
7. What caused the concrete to crack?

40. This is the central issue in the case. Both sides agree that the extent of cracking both within the warehouse building and on the outside driveway is unacceptable and such that with the passing of time and vehicular traffic it is likely to require total replacement in the external areas and substantial replacement in the internal areas. Neither party accepts any measure of responsibility for the cracking and each side blames the other totally. The experts called on behalf of the plaintiff say that the primary cause of the cracking was in the placement and curing techniques. The experts called on behalf of the defendant say that the primary cause is in the proportions of the ingredients of the mix. In the end I think that all the experts concede, while the parties and their lawyers do not, that there may be factors influencing the tendency to crack other than that regarded as the primary cause.

41. One controversial question is whether the ratio of sand to coarse aggregate in the plaintiff's mixes was too high. The plaintiff's batch cards (part of Exhibit M) show how a 5 m3 load is made up of the various constituents (except water) and they lead to the conclusion by all expert witnesses, which I accept, that the weight of dry aggregate and of sand is equal in mix 270/702 and nearly equal in mix 285/604. (This assumes a moisture content of 10 percent in the sand.)

42. On the subject of drying shrinkage cracking the difference in the views of the experts on either side was not so great as on the subject of plastic shrinkage cracking. The experts tend to agree that most if not all of the cracking on the internal slab is drying shrinkage cracking, although Prof. Roper takes the view that some of the internal cracking is plastic shrinkage cracking and that the plastic shrinkage cracking aggravated the later drying shrinkage cracking or some of it. The defendant's witnesses concentrated their evidence on the causes of plastic shrinkage cracking in the external slab. They said that such cracking was due to over-sanding of the mix and consequent use of excess water. It is consistent with their evidence that excess water will cause plastic shrinkage cracking and aggravate cracking at the drying shrinkage cracking stage. However, bearing in mind that some drying shrinkage cracking is inevitable and acceptable, I did not take the defendant's experts to be as firm on the proposition that the over-sanding of the mix was the primary cause of the drying shrinkage cracking in the present case as they were on the proposition that over-sanding was the primary cause of the plastic shrinkage cracking. Furthermore, it appeared to be generally accepted amongst all the experts that the failure to use jointing material to the full depth of the slab contributed substantially to the cracking internally and where the external slab abutted the wall. Despite the evidence (which I accept) of the internal concrete taking a long time to dry to the finishing stage and of the tendency of edges to crumble when finishing work was being carried out, I am not satisfied that drying shrinkage cracking would have occurred either in the internal or the external areas if adequate expansion jointing had been used. The jointing material was inadequate in that it did not penetrate the depth of the slab and was likely to contribute to restraint in the drying shrinkage stage. In my view, it was a substantial cause of such drying shrinkage cracking as occurred.

43. I turn now to the more controversial question of the cause of the external plastic shrinkage cracking. The experts called on behalf of the plaintiff were Professor Harold Roper, Associate Professor in the School of Civil and Mining Engineering at the University of Sydney, who holds a doctorate in Geology and a Master's degree in engineering in concrete technology, and Mr Peter Ellen, a consultant in concrete technology. More limited technical and expert evidence was given by Mr Paul Mahaffey, a chartered civil engineer. The technical evidence for the plaintiff came from Mr Frederick Beresford, a retired CSIRO scientist and now consultant in concrete technology and Mr Vincent Wallis, a consulting concrete technologist and formerly concrete technologist and quality controller on the Parliament House project from 1981 to 1986. Professor Roper and Mr Ellen tend to approach matters from a more academic and theoretical point of view. Messrs Beresford and Wallis draw rather from their experience in the field. In drawing attention to that difference in their approach I do not intend to convey that one approach rather than the other is more likely to achieve accuracy. It appears from the expert and technical evidence as a whole that concrete technology is not yet a very exact science and there are many aspects of the behaviour of concrete that are not yet well understood. Such lack of precision is not surprising given the variability of the factors which contribute to the performance of concrete, not the least of which are (on one view) atmospheric and climatic and hence uncontrollable or nearly so.

44. Professor Roper and Mr Ellen state categorically that the primary cause of plastic shrinkage cracking is in the constituent ingredients of the mix. They start from the premise that excess water in the mix will lead to cracking in the plastic stage. (I have already touched on the theory of why this occurs.) They go on to say that one situation in which plastic shrinkage cracking will occur is when a mix is "over-sanded". A mix is over-sanded in this sense where the ratio of sand to coarse aggregate is so high that the mix is unworkable without the addition of excess water. Their view stated broadly is that the ratio of sand to coarse aggregate should be no higher than 30 to 40 percent sand to 60 to 70 percent coarse aggregate and that where the proportion of sand is so high that it is approximately equal to that of coarse aggregate then so much water has to be added to make the mix workable that plastic shrinkage cracking can be expected to occur.

45. Messrs Beresford and Wallis, on the other hand, say plastic shrinkage cracking occurs where the rate of evaporation at the surface of the concrete exceeds the rate at which the water within the concrete is able to diffuse to the surface. They do not deny that the rate of diffusion may be affected by the constitution of the mix but they lay emphasis on over-rapid drying, which appears (to me) to be another term for improper or inadequate curing. They say that further if the mixes supplied by the plaintiff to the defenant were made up by the despatcher according to the requirements of the batch cards, then the mixes were not over-sanded and that equal proportions in weight of coarse aggregate and sand were common in typical concrete paving mixes in Australia at the time in question.

46. Professor Roper and Mr Ellen in contrast take the view or appear to take the view that evaporation at the surface is not the important factor. The important factor for them is the pressure generated by the hydration process which drives the water in the concrete to the surface. It seems, although they do not appear to have said so expressly, that where there is excess water in the mix, it is this pressure which seeks release where there is least resistance, that is, at the surface and hence causes cracking at the surface. Hence, according to Professor Roper and Mr Ellen, plastic shrinkage cracking can occur even under water. Indeed, according to Mr Ellen, "complete curing" can be effected only if there is sufficient pressure at the surface to counter the pressure within the hydrating concrete, pressure which would otherwise be released at the surface. Such counteracting pressure, according to Mr Ellen, can be achieved only under a depth of two to five metres of water. In contrast, Mr Beresford expressed the view that because plastic shrinkage cracking is caused by rapid evaporation, all that is required to prevent it is to keep a film of water, no matter how thin, on the surface.

47. Where the experts are in such disagreement on a fundamental issue, a lay person or lawyer has to tread very warily. However, in litigation, decisions on certain fundamental issues may not be avoided no matter how difficult. The law requires that reasons for decision be given, not least so that the losing party can identify grounds of appeal. The reasons in this case are not proffered as a contribution to science but as part of the judicial process. In my view, the approach of Messrs Beresford and Wallis begins with the superficial attraction of being more easily understood. Mr Wallis illustrated the application of his views by reference to the absence of any curing problems or cracking of concreting works at Parliament House where a vast quantity of paving concrete was placed. Mr Wallis took the view that such problems were avoided there by the application of an anti-evaporative compound almost immediately after the placement of the concrete. (Of course this argument invites a rejoinder that at Parliament House a proper mix, without excess water and not over-sanded, was used and Mr Wallis was not asked and did not tell us what the makeup of the mix at Parliament House was.)

48. Professor Roper and Mr Ellen say that plastic shrinkage cracking can occur under water, but neither of them stated that he had seen such a thing occur nor cited an example in the literature of any such thing being recorded. The plaintiff's experts conceded that excess water can contribute to cracking in concrete, including plastic shrinkage cracking. They also conceded that over-sanding of the mix will tend towards the use of excess water. On this latter approach I draw the conclusion that a mix which is over-sanded, even slightly over-sanded, is more likely to be susceptible to rapid drying and hence to plastic shrinkage cracking. Mr Wallis himself said so and that seems to be at the heart of the explanation of why the external concrete at the Fyshwick site was subject to plastic shrinkage cracking. That is not to say, however, that the curing and placement techniques may not in general and in this case contribute to the development of plastic shrinkage cracking.

49. I mention at this stage the submission on behalf of the defendant relating to what was alleged to be inadequate control of the amount of water added to the mix at the batching plant. I have considered the point that the evidence from the plaintiff on this aspect does not establish convincingly that the quantity of water added at the batching plant was a matter of precise calculation on each occasion. There was some evidence that the quantity to be added is the subject of an exact formula worked out in a laboratory. On the other hand, much seems to depend on the experience and intuition of the despatcher. No slump test is carried out at the batch plant, and presumably that would be impracticable because the ingredients have not been mixed when the delivery truck departs the plant. The responsibility of ensuring that a satisfactory slump is reached prior to delivery at the work site is that of the truck driver. As a matter of practice the despatcher will tend to add too little rather than too much water. The despatcher will take into account the moisture content of the sand, for which he tests at the beginning of the day. Any inadequacy in the plaintiff's practice or in the tests conducted by it was not demonstrated in evidence.

50. It was also suggested on behalf of the defendant that the making up of one cubic metre of concrete from the ingredients as shown on the batch cards would involve the addition of a volume of water well in excess of the average water content of a number of actual concrete mixes which were the subject of studies in 1979 and 1985. Those studies were themselves the subject of evidence from Mr Beresford and Mr Wallis. On behalf of the defendant it was sought through the cross-examination of those witnesses to correlate the figures in those studies of what was typical in mixes supplied in the industry with the figures shown in the plaintiff's batch cards which were in evidence. I do not wish to demean the quality of the argument by avoiding lengthy discussion of this issue. I find the argument unconvincing chiefly because the standard of a single cubic metre is not in the concrete industry an invariably exact one. It was no part of the defendant's case at any stage that the plaintiff supplied less than the quantities it claimed to have supplied. To argue that the two batch mixes in question would have required the addition of about 200 litres of water in each cubic metre (whereas the mixes the subject of the 1979 and 1985 studies in fact required 173 litres per cubic metre and from 155 to 185 litres per cubic metre respectively) is to engage in theoretical and hypothetical issues which in the light of other explanations do not require resolution.

51. I adopt a similar approach to the argument that the plaintiff's mixes contained more fine aggregate or sand than appears at first glance. This was said to be so because the plaintiff adopted and applied a definition of sand which included only aggregate materials which passed through a 2 mm sieve, whereas it was a commonly held view in the industry that aggregate materials passing through a 4.75 mm sieve should also be regarded as fine aggregate or sand and not as coarse aggregate. Further, on this issue the defendant relied on some evidence that the plaintiff's aggregate test sheets showed that what was classed by the plaintiff as 10 mm and 20 mm aggregate contained a proportion of material which would pass the 4.75 mm sieve and hence should be classed as fine aggregate or sand. Mr Wallis agreed when these matters were put to him and, assuming the validity of the argument to that point, that the sand ratio would be raised to 49.8 percent for mix 286/604 and 50.5 percent for 270/702 concrete. However, in my view, these proportions are not such as to necessarily cause plastic shrinkage cracking without the intervention or addition of other factors such as inadequate curing techniques and the addition of water at the site. To carry this reasoning one stage further, I am not convinced that those proportions were such that they were likely to cause plastic shrinkage cracking at the Fyshwick site on 6 November 1987 and during the following week without the intervention or addition of those other factors. I turn now to what happened at the site.
8. What happened at the site?

52. There is a good deal of evidence, some of which is contradictory, relating to the handling of the concrete once it arrived at the site. Several distinct matters need consideration. They are: the speed at which the work was done, the addition of water to the mix at the site and before placing, the covering and wetting down of the concrete after placing (curing), the level of the reinforcing steel within the slab, uneven subgrade, use of slagment and the depth of saw cut joints. I discuss each in turn.
9. Speed of work

53. The amount of concrete ordered for delivery on 6 November 1987 was much higher than that ordered on any previous or subsequent day. It does not appear that any extra concrete workers were hired. Mr Lentini said that he ordered trucks to arrive at ten minute intervals. The records, however, indicate that the first truck left the batching plant at 6.45 a.m. and thereafter at irregular intervals, the second last load being at 9.30 a.m. and the last at 10.03 a.m. The batching plant was only a few minutes from the delivery site. There were twenty-five deliveries altogether and the average interval between loads would have been about eight minutes. Between truckloads the concreters were required to screed and pack down the concrete with vibrating machines. If the vibrating work is not carried out properly, then settlement cracking is likely to occur which in turn can give rise to so-called planes of weakness to which any later plastic shrinkage cracking will be attracted. The evidence suggests that bleed water on the day in question had evaporated and the concrete was hard enough to walk on about two hours after the time of placement. It would accordingly have been possible from about 8.45 a.m.to start covering the concrete to avoid rapid evaporation. In fact the concrete finishing was not completed until about 2 p.m., nearly four hours after the last pour. This suggests that the concrete finishing work did not keep pace with the delivery of the loads. These circumstances increased the risk that proper techniques might not be applied to the placing, finishing and curing of the concrete.
10. Was water added at the site?

54. There was evidence from several witnesses to support the plaintiff's contention that water was added to the concrete after its arrival at the site. The most compelling evidence on this aspect, in my view, was given by the plaintiff's field tester, Mr Arnold Butt. Mr Butt was in some ways an easy target for the cross-examiner on peripheral issues. He was obviously embarrassed by inaccurate recordings in his field sheets which suggested that he tested three samples on each occasion, when in fact he tested only two. Nevertheless, Mr Butt was unshaken on his observations of concreters at the site adding water to the barrels of the delivery trucks. He said that water was added in this way to most of the trucks he observed on the site when the internal bays were being poured and to about half of the trucks observed when the external part of the slab was being poured. It is true that he attended the site on three occasions only, namely on 20 and 22 October and 6 November 1987, but there is no reason, in my view, to regard what Mr Butt observed as being exceptional. A slump test carried out by Mr Butt on 6 November 1987 recorded a 130 mm slump which is clearly indicative of the addition of excessive water. A field test sheet bears the notation "water added by customer". Another field test sheet completed on that day bears the notation "water added after testing". Less persuasive but consistent with the evidence of Mr Butt was that of Mr Peter Schmidt who was employed by an independent field testing organization. Indeed, Mr Schmidt contended that on occasions he observed the concreters adding water to the mix and unsuccessfully tried to prevent them from doing so. He added, however, that water was added to less than ten percent of the total which he saw delivered. Although it is impossible to come to any firm conclusion about how much water was added to individual deliveries, or about what proportion of the deliveries had water added to it, I have little hesitation in reaching the conclusion that in relation to both the inside and outside part of the slab the concreters added water to the mix at the site and prior to it being poured. Indeed, the likelihood that water was added is consistent with the defendant's case that the mixture was over-sanded. Furthermore, particularly on 6 November 1987, the addition of water is consistent with the need of the concreters to work at extraordinary speed in order to try to keep up with the deliveries. The concreters were likely to be particularly sensitive to concrete which was not easily workable and hence more likely to make it easily workable by adding water.
11. Curing: Covering and watering down of finished concrete

55. Statements tendered in evidence from Mr Dominic Lentini, Mr Bailey and Mr Frank Barbaro, assert that prior to the concreters leaving the site at about 2 p.m. the concrete was hosed down. However, in their oral evidence none of them was prepared to adhere to that assertion. Mr Bailey said that he did not see hessian being wet down that afternoon, but that rain had started before the men had left the site. Mr Barbaro and Mr Dominic Lentini said in evidence that the watering down occurred at about 4 p.m. upon their return to the site. Why they found it necessary to return to the site at 4 p.m. is not clear (it is also unclear why it was Mr Barbaro who was first to return at 6 a.m. the following day). The men had obviously worked long and hard until 2 p.m. and needed a break. However, the break they took was a long one. They stayed at the tavern until about 4 p.m. The concrete at that stage was, as I find, still uncovered. I am satisfied that somewhere during the afternoon a light drizzle of rain fell. That may have encouraged the men to stay at the tavern without hurrying back to cover the concrete. I am not satisfied, however, that more than a slight drizzle or shower of rain fell. I accept that Mr Barbaro did cover a proportion, probably about ninety percent of the concrete, with plastic and hessian, but I am not satisfied that he did so until about 4 p.m. or after. I am unable to determine whether the drizzle or shower of rain fell at the site before or after Mr Barbaro placed the hessian and plastic over the concrete. It was not the defendant's representatives whom Mr Barbaro contacted next morning but Mr Bailey, the representative of the proprietor. Mr Bailey does not appear to have contacted Mr Ross Lentini or anyone else on behalf of the defendant until the Monday. Mr Bailey was not an entirely disinterested witness. Mr Barbaro's role in any event was a curious one. He was not a concreter at all, and he was not engaged by the defendant. On this aspect of the case I accept entirely, as far as it goes, the evidence of Mr William Martin, one of the concretors, who remembered that there was a shower whilst they were at the tavern, but he could not remember how heavy it was or how long it lasted, except that it was probably between one minute and half an hour.

56. The evidence of Mr Wallis suggested that with the amount of hessian and plastic sheeting on the site it was impossible for as much as ninety percent of the area to be covered. It is not necessary to make a positive finding on that exact matter. What that evidence and the rest of the evidence does show is that the defendant failed to provide on the site enough hessian and plastic sheeting to completely cover the area poured on the day in question.

57. Apart from the drizzle or shower of rain which fell in the afternoon, the weather on the day in question was dry with some sunny periods in the morning, tending towards being overcast in the afternoon. Meteorological records for Canberra show that the ambient temperature was fifteen degrees at 9 a.m. and twenty degrees at 3 p.m., with the relative humidity being sixty-seven percent at 9 a.m. and forty-three percent at 3 p.m. It is not clear where these readings were taken but temperatures and humidity would not vary much in different parts of central Canberra. On the other hand, the rainfall recorded at the Fyshwick observation site of the Bureau of Meteorology, only two hundred metres or so from the site, was 0.4 mm during the twenty-four hours ending 9 a.m. on 7 November 1987. There was considerably more rain over the next few days. Light breezes were recorded on 6 November. I conclude from these records that apart from the shower or drizzle that fell in the afternoon the day appears to have been relatively warm and dry. Mr Beresford calculated from the meteorological records that the evaporation rate in the afternoon of 6 November 1987 was 0.6 kilograms per square metre per hour. He also expressed the view that where the rate of evaporation is above 0.5 kilograms per square metre per hour, then particular care should be taken to avoid rapid drying. He rejected the view put that no particular measures are necessary until the evaporation rate reaches or exceeds 1.0 kilograms per square metre per hour. Whilst the scientific exactness of this evidence is probably not great, I think that broadly it should be accepted.

58. In the light of the above, I conclude that the concrete was not covered until about or after 4 p.m. on the afternoon of 6 November, that it was not watered down prior to it being covered except to the slight extent to which rain may have fallen and that the hessian covering was not watered down except again to the slight extent that rain fell after the covering was put down. In those circumstances, the possibility of plastic shrinkage cracking occurring was substantially increased.

59. I observe at this point also that the meteorological records show more substantial rain on the days following 7 November.
12. Steel reinforcement

60. One effect of steel reinforcement in a concrete slab is to minimize the width of such cracks as occur in the concrete once it hardens. The reinforcing steel will have little influence in this regard unless it is placed towards the top of the slab rather than towards the bottom. The evidence is clear in this case that as far as the outside slabs are concerned, the reinforcing steel was not placed on the "chairs" which are the usual method of keeping the steel high in the slab. Because of the quantity being poured on 6 November 1987 and the speed at which it was poured, the reinforcing steel was laid out flat on the base and each truck backed over the steel until it reached the point where the particular delivery was to be poured. The truck then moved forward discharging its load and as it did so, the concreters raised the steel mesh manually or with their shovels, then packed the concrete around and under the steel mesh so that it was the concrete itself that kept the mesh clear of the very bottom of the slab. Subsequent core tests showed the steel to be towards the bottom of the slab and not towards the top, which is entirely consistent with the unusual and hasty method used to keep the steel raised. Because the steel was at that level it failed to hold the edges of the cracks together and thus contributed to the widening of such cracks as occurred.
13. Uneven subgrade

61. There is evidence that the external concrete varied in depth between 115 mm and 150 mm. This evidence is provided by core samples taken by Mr Wallis or Mr Mahaffey. The engineering specification provided for a thickness of 150 mm. Whilst it is possible that the depth of the concrete was graded evenly between its minimum and its maximum thicknesses, this is, in my view, less likely than the alternative possibility that the base of the subgrade was uneven. The effect of an uneven subgrade is to restrain the movement of the slab when shrinkage occurs at the drying stage and it is therefore a likely cause of drying shrinkage cracking. Although Mr Bailey and other defence witnesses who observed the work done on the subgrade say that the preparation was satisfactory, their observations do not stand up against the objective evidence of the core samples. I am aware of the possibility that the core samples may be misleading in the sense that they happen to be samples of exceptional and not typical areas. On the other hand, Mr. Bailey tended towards over-enthusiasm. The other witnesses were not entirely satisfactory in other parts of their evidence and that affects their overall credibility. None of the witnesses was able to speak of precise measurements taken during the subgrade work or on its completion. The engineer who was said to have approved the subgrade work was not called. Accordingly, in my view, the uneven subgrade was in itself another possible cause of the restraint cracking both within the building and at those places on the external slab where it abuts the building and other fixed structures such as fence posts and brick walls. Taken alone it was not a likely cause. Taken into account with other causes, it was a likely contributor.
14. Use of slagment

62. Although slagment is in common use for paving mixes in Europe, it is not commonly used in the United States, and until recently was not in common use in Australia. Mr Wallis said that it had not come "on stream" at the time design mixes were chosen for the construction of Parliament House and it was not used at all in the concreting works on that project. On the other hand, the defendant's witnesses did not assert that slagment was an unsuitable component in concrete or that it was of itself causative of cracking. What they did say was that slagment tends to react more slowly in the hydration process so that in the early stages, the first two or three days, there is a greater proportion of free water in the mix. Consequently, on either view of what it is that causes plastic shrinkage cracking (whether it is the pressure generated by the hydration process or the rapid drying out of the surface) it would seem that the presence of slagment might tend towards the development of plastic shrinkage cracking in adverse climatic conditions.

63. It is also worthy of comment that the plaintiff did not call any evidence from the shipper or anyone else to explain why the particular mixes containing slagment were chosen by the plaintiff for supply to the Fyshwick site. Batch 270/702 was, according to the batch card, intended for specific use as a pumped mix. Why the Type A component was replaced by the slagment component in that mix is not the subject of any explanation on the part of the plaintiff. It is notable that the weight of slagment in the 270/702 mix as supplied is slightly and consistently less than what the Type A cement component would have been. The inference is that someone has given thought to the substitution, that it has not occurred accidentally and that it has been considered appropriate to reduce the weight of the cementitious binder accordingly. In relation to the mix chosen for the external part of the slab, although there is no case made on the part of the defendant that a slagment mix was inappropriate, the plaintiff offers no explanation why a slagment mix was selected. The plaintiff's records indicate that the batch mix 285/604 was used only in a very small proportion of concrete supplied to its customers and the bulk of batch mix 285/604 supplied in the period reviewed was supplied to the defendant at the Fyshwick site. The explanation why it was that slagment was chosen seems to me to be found in the fact that this was a competitive job as far as price was concerned. The brochure of the slagment manufacturer promotes the product as "the economical alternative". The original verbal quote of $101 per cubic metre was reduced to $100.50 per cubic metre when Mr Ross Lentini informed Mr Dryden that he could obtain concrete from an alternative source at the lower price, although the price was later increased to accommodate the higher required strength.
15. Inadequate saw cut joints

64. Whilst the concrete in the interior of the warehouse was poured in formed bays with constructed joints between the bays, the concrete poured each day on the external part of the slab was not poured in separate areas in this way. What was planned to be done on the external slab was that the morning after each pour saw cut joints were to be cut into the slab in panels measuring nine metres by nine metres. Those dimensions were to match some existing and adjoining concrete work. The fact that the existing concrete work appeared to be satisfactory, is indicative that the size of the panel was not of itself something which would necessarily cause cracking, although six by six metres is a more commonly used area for concrete paving panels. On the other hand, the purpose of the saw cut joints was not merely cosmetic. Because the cause of cracking in concrete is essentially connected with shrinkage and some cracking is inevitable, strategically placed saw cut joints may be used create planes of weakness to which subsequent cracking, particularly drying shrinkage cracking, will tend to be attracted. In the present case the saw cut joints in the external slab were cut to a depth of about 25 mm only. To be effective they should have been at least half the depth of the slab. In the case of the concrete poured on 6 November, the saw cut joints were not cut into the slab until 9 November. Hence there was, in my view, a likelihood that the joints cut on 9 November, or some of them, would not be effective to achieve their purpose and that plastic shrinkage cracking and drying shrinkage cracking would occur other than at the saw cut joints.
16. Effect of Findings of Fact

65. I am not convinced that the concrete delivered would have been subject to plastic shrinkage cracks of significance or to unacceptable drying shrinkage cracking without the other factors I have mentioned for which the defendant is responsible, namely the addition of water to the mix at the site and, in relation to the external work, inadequate curing techniques. In reaching this conclusion I acknowledge that the work done on the external slab after 6 November resulted in similar and unacceptable cracking to that which occurred in the concrete poured on 6 November, despite the care that the defendant's witnesses say was taken after 6 November not to hasten the work and to keep it covered to prevent early drying. These witnesses also said, somewhat paradoxically, that they used the same curing methods after 6 November as they did on that date. I have found that the curing techniques used on 6 November were inadequate and were a substantial cause of the cracking of the concrete poured on that date. If as the defendant's witnesses assert, the techniques used after that date were the same, then they would be of the same inadequate character. In any event, some of the 285/604 mix delivered on 11 November was used for internal work and no unacceptable cracking occurred there, a fact highly suggestive that the external concrete continued to be subject to rapid early drying and hence plastic shrinkage cracking. I take full account of the fact that the BMG concrete used to finish the job after 13 November caused no significant problems. That fact of course tends to support the defendant's case, but it is not decisive. No one was called from BMG to describe either the constituents of the mix or the curing techniques that were used at that stage. One would assume that at that stage everything possible would have been done by the defendant to ensure that there was no repetition of what had happened with the concrete supplied by the plaintiff. That the BMG concrete was cured effectively, is undoubted, because it did not crack to an unacceptable extent and it may well have been that by that stage the defendant was following proper curing practices.

66. In the circumstances, I conclude that the defendant has not proved that the concrete supplied by the plaintiff was not of merchantable quality. I am not convinced that a buyer, aware of the relevant facts, would not have bought the concrete that was in fact delivered by the plaintiff to the defendant on the days in question. The relevant facts that a buyer would have taken into consideration included the composition of the mix, the coarse aggregate and sand ratios and the inclusion of slagment. Another relevant fact was that both mixes were "off the shelf" mixes, which were supplied to other customers from time to time and that such mixes were likely to be exposed to a risk of cracking if water was added to the mix at the site and if the concrete placed was not cured correctly. The hypothetical buyer would, in my view, be like the defendant, a person in the business of concrete contracting. A buyer in that position would, in my view, not have refrained from purchasing the concrete that the plaintiff in fact supplied.

67. For similar reasons, in my view, the defendant has not shown that the concrete was not at the time of its arrival at the site, reasonably fit for the purpose of providing an internal and external concrete slab capable of bearing the load of vehicular traffic. Similarly, the defendant has not shown that the plaintiff failed to use due care and skill in mixing and delivering the concrete on each of the occasions in question. Lastly, although the plaintiff agreed to supply a mix containing Type A Portland cement only on 19 October 1987 and was in breach of that promise, the defendant has not shown that that breach resulted in the cracking complained of or in any other damage. Nor has the defendant shown that the aggregate contained too little 20 mm aggregate or excessive slump.

68. These conclusions point to the formal orders that should be made, namely judgment for the plaintiff against all defendants in the action for an amount to be determined, judgment for the plaintiff in the first defendant's counterclaim, all defendants to pay the plaintiff's costs in the action and the first defendant to pay the plaintiff's costs in the counterclaim.

69. However, the parties have asked that I hand down my decision without making any formal orders, with a view to short minutes being brought in by the parties. I understand that this course may assist in other litigation involving Iannelli and Atlantic Civil. In accordance with the parties' wishes I simply publish these reasons and give leave to bring in short minutes within seven days. I adjourn the case to a date for mention to be fixed by arrangement with the list clerk.