1、 ERRATA ACI 224R-01 Control of Cracking in Concrete Structures Reported by ACI Committee 224 Page 224R-13, Section 3.4.2, revised as: 3.4.2 Influence of quantity and type of aggregate on shrinkageConcrete shrinkage is due primarily to shrinkage of the hardened cement paste.This is also illustrated i
2、n Fig. 3.4, where an elastic modulus ratio between 1 and 2 indicates an aggregate stiffness that is much smaller than that of normalweight aggregate. Constitutive models for predicting the influence of relative aggregate content and modulus ratio on ultimate concrete shrinkage have been developed by
3、 Pickett (1956) and Hansen and Almudaiheem (1987). Pickett (1956) and Hansen and Almudaiheem (1987) developed constitutive models for predicting the influence of relative aggregate content and modulus ratio on ultimate concrete shrinkage. The latter model clearly explains why lightweight concrete fo
4、r the same relative aggregate content exhibits considerably more shrinkage than ordinary concrete. This is also illustrated in Fig. 3.4 when the modulus ratio is between one and two because the aggregate stiffness is much smaller than that of normalweight aggregate. The influence of aggregate-absorption capacity on concrete Page 224R-21, equation for t1: Currently reads: = active steel ratio, that is, the area of steel Asper ft width/12db1+ 2c1, It should read: = active steel ratio, that is, the area of steel Asper ft width/12(db1+ 2c1),. Updated on 3/24/2008
