CONCRETE IN HOT ENVIRONMENTS - CHAPTER 3 potx

... in porosity was not always observed and, in fact, an increase in the Fig. 3. 13. Temperature rise measured in mass concrete. Control mix contained 400 kg/m 3 ordinary Portland cement (OPC). In the ... strength of concrete. (Adapted from Ref. 3. 15.) Copyright 19 93 E & FN Spon intergrounding, or by intimately mixing their constituents. That is, the preceding sections (3....

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... edition 19 93 © 19 93 E & FN Spon ISBN 0-2 0 3- 4 736 3- 9 Master e-book ISBN ISBN 0-2 0 3- 7 818 7-2 (Adobe eReader Format) ISBN 0 419 15970 3 (Print Edition) Apart from any fair dealing for the ... hydration 3. 1.2 .3. 2 Microstructure 3. 1.2 .3. 3 Calcium hydroxide content and pH value of pore water 3. 1.2 .3. 4 Strength development 3. 1.2 .3. 5 Other properties...

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... added during the grinding of the cement clinker (section 1.1). The gypsum combines with the C 3 A to give a high-sulphate calcium sulphoaluminate, known as ettringite (3CaO·Al 2 O 3 ·3CaSO 4 31 H 2 O), and ... 1.8.) Copyright 19 93 E & FN Spon 1 .3. MINOR CONSTITUENTS 1 .3. 1. Gypsum (CaSO 4 ·2H 2 O) It was pointed out earlier (section 1.2 .3) that the C 3 A reacts with water almo...

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... its initial and final setting Fig. 2.15. Effect of placing tempera- ture on temperature rise in mass concrete containing 2 23 kg/m 3 of type I cement. (Adapted from Ref. 2.18.) Copyright 19 93 E ... discussed in some detail in Chapter 3 and, indeed, the temperature rise in concrete made of such cements is lower than the rise in temperature in concrete made with OPC....

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... (1982), 429 32 . 4.20. Ravina, D., Slump loss of fly ash concrete. Concrete Int., 6(4) (1984) 35 –9. 4.21. ACI Committee 30 5, Hot- weather concreting (ACI 30 5R-89). In ACI Manual of Concrete Practice ... Proc. J. ACI, 74(8) (1977), 36 1–7. 4.9. Hampton, J.S., Extended workability of concrete containing high-range water- reducing admixtures in hot weather. In Development...

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... cement), and 2 and 6 (10 min mixing time, 34 0 kg/m 3 cement). In fact, the effect of fly-ash was quite significant, increasing, in the case of 10 min mixing, plastic shrinkage by approximately ... when the shrinkage curves are compared for the same mixing time and original cement content, i.e. curves 4 and 5 (60 min mixing time, 280 kg/m 3 cement), 1 and 3 (60 min mixing time, 34...

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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 ... carry out such work as form stripping and cleaning, setting of reinforce- ment, and other wall maintenance in preparation for the next pour. A 30 in. (762 mm) wide working platform also allows...

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... corresponding increase in the modulus of elasticity. (3) Joints should be provided in concrete members in order to reduce the restraining effect of the structure on shrinkage. It is self-evident ... a finer pore structure see (Chapter 3, Figs 3. 3 and 3. 15) and sometimes also by a lower porosity (Chapter 3, Fig. 3. 14 ). On the other hand, considering shrinkage mechanisms (se...

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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 ... Z., Shrinkage and creep of mortar and concrete as affected by hot- humid environment. In Proc. RILEM Symp. on Concrete and Copyright 19 93 E & FN Spon in areas of hindered ad...

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... with the alumina-bearing phases of the hydrated cement to give a high- sulphate form of calcium aluminate (3CaO.Al 2 O 3 .3CaSO 4 .32 H 2 O, i.e. C 3 A.3CS¯.H 32 ), known as ettringite. The formation ... with a low C 3 A content. In other words, in producing sulphate- resistant concrete, the use of sulphate-resisting cement must be combined with a specified minimum cement conten...

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