This paper provides details on five projects where high-performance concrete was used for construction of concrete floors and pavements. Four of these projects are located in Australia and one in Malaysia. Emphasis is placed on strict quality assurance in accordance with AS/NZS 9002 Quality Systems for Production and Installation. Assessment of the concrete quality was made in accordance with the inspection and test plan proposed by the concrete manufacturer and the project specification. The main assessment criteria for each of the following projects were performance based. Chullora printing facility used 80-MPa and lOO-MPa concrete to achieve a very high abrasion resistance, very flat floor to accommodate the continuous turning actions of computer guided vehicles transporting full rolls of newsprint. lOO-MPa textured road pavement was constructed at Wilton Road, Maldon to facilitate frequent turning of heavy vehicles on a public road adjacent to the cement works. National Rail Corporation freight terminal crane roadway was constructed at Chullora using lOO-MPa concrete with a 10-MPa flexural strength. The roadway was subjected to road loadings 24 hours after concrete placing. A distribution centre at Bukit Raja in Malaysia, for which a 40-MPa concrete was specified for the construction of a very flat floor with a high abrasion resistance. An 80-MPa concrete was specified for the construction of a trial pavement for the network of roads within the North Parkes underground gold mine in western New South Wales. The performance criteria was consistently achieved on each project, due to a very well co-ordinated team effort. Because normal concrete is not suitable for this type of construction, high-performance concrete must be specially designed in conjunction with specific methods of floor or pavement construction to yield significantly reduced overall maintenance and life cycle cost savings.

Fiber reinforced concrete has been used for shotcrete concrete structures, floors and pavements structures and precast applications. Recently, fiber reinforced concrete has been applied for repairing and strengthening the bridge structures which are deteriorated by heavy traffic load, corrosion and freezing and thawing action. One of the most popular repair/strengthening methods is overlay techniques to increase the slab thickness. In this case, the fiber reinforced overlay structures are required to be high fracture toughness in compression as well as in flexure. However, the compressive toughness of fiber reinforced concrete has not been sufficiently studied, although there are many reports about the flexural toughness. In this paper, fracture toughness of fiber reinforced concrete is studied in compression as well as in flexure. Four different types of steel fiber and two types of polyvinyl alcohol (PVA) fiber were used with two types of fiber together or as single types of fiber. Hybrid effects of fracture toughness in compression as well as in flexure were investigated by mixing the steel and PVA fiber. The simple effects of fiber type, fiber content, fiber geometry, on fracture toughness were also investigated with using steel fiber and PVA fiber by themselves.

Experimental tests were carried out on 150* 150*600 mm high strength concrete beams containing 1.0% of hooked-end steel fibers. Concrete with compressive strength up to 117 MPa was used. The test results showed that the first-crack strength depends primarily on plain concrete characteristics rather than fiber parameters. After the occurrence of the first-crack, the fibers effectively work, carry the entire applied load, and tend to suppress the localization of micro-cracks into macro-cracks and consequently the flexural strength increases. Two equations are proposed for predicting the flexural strength of high strength concrete with and without fibers. The test results indicated that the use of 78 kg/m’ of hooked type steel fiber can easily provide toughness indices as high as 5, 10, and 30 for I5 , I10 , and I30 respectively. However, toughness Indices at higher deflection, such as I5 0 and I100 depending on service conditions are highly desirable to fully identify differences present in the load-deflection (P-6) curve. The relative post-crack strength helps to distinguish post-crack performance differences more clearly than toughness index because it reflects the shape of the P-6 curve over a specific deflection interval, rather than over the whole of the post-crack portion of the curve.

The short term performance aspects of portland limestone cements (setting, concrete slump, strength development and heat of hydration) are compared with those of portland slag, fly ash and pozzolanic cements. The early activity of the portland limestone cements, as indicated by initial setting time, early strength and early heat release, is generally higher than that of the other cement types. Ultimate strengths are, however, lower provided moist curing conditions are maintained. The longer term performance characteristics of, concrete carbonation rate, freeze-thaw resistance, sulfate resistance and chloride penetration are also compared. Generally the performance of cements containing up to 25% limestone was satisfactory and within the range of performance of the portland cements from 4 different sources. Portland limestone cements with similar late strengths and superior early strengths to normal portland cements can be produced if active mineralised clinker is used as the basis of the cement. The environmental impact of cement manufacture is reduced with this type of cement. The effective utilisation of portland limestone cements is dependent upon having appropriate cement and concrete standards in place. The European countries have largely achieved this and are in a good position to gain the economic and environmental advantages of portland limestone cement manufacture and use.

An investigation of moment redistribution effects in high strength concrete beams is described. Results from a test programme involving six two-span beams are presented. Three beams contained strain gauged reinforcing bars for making detailed measurements of reinforcement strain distributions. Results are compared with those from previous tests on similar beams made with normal strength concrete. Design implications are assessed.