CONCRETE IN HOT ENVIRONMENTS - CHAPTER 5 doc

... mainly on the building site, and the latter mainly in the production of glass-fibre-reinforced concrete products, commonly known as GRC products. A detailed discussion of fibre-reinforced concrete ... pp. 4 35 41. 5. 15. ACI Committee 3 05, Hot weather concreting (ACI 3 05, R-89). In ACI Manual of Concrete Practice (Part 2). ACI, Detroit, MI, USA, 1990. Copyright 1993 E & F...

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... a minimum loss homogeneity’ (ASTM C1 25) . In this definition the term ‘manipulate’ is meant to include all the operations involved in handling the fresh concrete, namely, transporting, placing, ... PA, USA, 19 85, pp. 66–87. 4.24. Tipler, T.J., Handling. In Proc. Intern. Seminar on Concrete in Hot Countries. Helsingor, 1981, Skanska, Malmo, Sweden, pp. 71–9. 4. 25. Anon., Keepin...

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... Spon 5. 2.1.2 Cement and mineral admixtures 5. 2.1.3 Water content 5. 2.1.4 Chemical admixtures 5. 2.1 .5 Fibre reinforcement 5. 2.2 Plastic shrinkage cracking 5. 3 Plastic settlement and cracking 5. 4 ... superplasticisers 4 .5 Summary and concluding remarks References 5 Early Volume Changes and Cracking 5. 1 Introduction 5. 2 Plastic shrinkage 5. 2.1 Factors affecting plastic...

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... heterogeneous material made up of several fine-grained minerals which are formed during the clinkering process. Four minerals, namely Alite, Belite, Celite and a calcium-aluminate phase, make up some 90% ... water, hydration takes place bringing about setting and subsequent hardening in a few hours. If not allowed to dry, the resulting solid gains strength with time mainly during the first...

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... length of time in which cement mixes, including concrete, remain plastic and workable, and can be handled and used on the building site. Accordingly, a minimum of 45 min is specified in most standards for ... ‘hardening’. These stages of setting and hardening are schematically described in Fig. 2.1. The initial and final setting times are of practical importance. The initial setting t...

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... measured in mass concrete. Control mix contained 400 kg/m 3 ordinary Portland cement (OPC). In the fly-ash concrete 30% of the OPC was replaced by fly-ash and in the slag concrete 75% of the ... grains and, thereby, reduce the spacing between the solids. Hence, on subsequent hydration, the resulting capillary pores in the silica-fume- containing paste are much finer than the por...

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... made of aluminum (all-aluminum), ply- wood face and aluminum frame, plywood face and steel frame, and steel. All-aluminum gang forms consist of aluminum sheathing supported by an aluminum frame ... wales (single wale) or inserted be- tween them (double wale) to resist the lateral pressure of plastic (wet) concrete. An inclined bracing system is used to resist con- struction and wind loading...

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... of concrete shrinkage. Rev. Mater. Constr., 54 5 (1961), 79– 85 (in French). 7.13 Pickett G., Effect of aggregate on shrinkage and a hypothesis concerning shrinkage. Proc. ACI, 52 (5) (1 956 ), 58 1–90. 7.14 ... humidities indicated (wind velocity 20 km/h), on shrinkage of concrete containing 350 kg/m 3 ordinary Portland cement. Drying at 20°C and 50 % RH from the age of 28 days to...

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... not indicated by the data of Fig. 8.13 implying, in turn, that some other mechanisms may be involved. 8.4.2.4. Mineral Admixtures In discussing the effect of mineral admixtures on drying shrinkage ... load, shrinkage occurs simultaneously. Accordingly, creep is the increase in deformation with time under a sustained load excluding drying shrinkage. This is demonstrated in Fig. 8.1 for...

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... considered, e.g. in concrete exposed to sulphate-bearing soils or sulphate-containing water (Table 9.2). On the other hand, it can be concluded from the very same data of Fig. 9 .5, that the increased ... sulphate-resisting cement must be combined with a specified minimum cement content. Indeed, this conclusion is reflected, for example, in BS 8110, Part 1, 19 85, which specifies such a...

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