Use of Construction and Demolition Waste as Aggregate: Properties of Concrete - Recycled Aggregate in Concrete - page 325

Fig. 5.85 Expansion of concrete with 20 MPa design strength: a OPC as binder b OPC-30 % FA
as binder (Limbachiya et al. 2012 )
solution due to the replacement of 50 and 70 % of OPC by ggbfs (Fig. 5.86 ). Lee
et al. ( 2008 ) observed lower expansion of cement mortar due to the replacement of
50 % of fine NA by two types of fine RCA with different water absorption capacity
when the hardened specimens were kept under sodium sulphate and magnesium
sulphate solutions up to 15 months. On the other hand, at 100 % replacement
level, depending upon the quality of RCA, the expansion was comparable or
significantly higher than that of the conventional mortar. The mortar with higher
water absorption capacity has higher expansion than the other one (Table 5.26 ).
Lee ( 2009 ) reported that the magnesium sulphate resistance of cement mortar
with replacement of NA by fine RCA depended on the replacement ratio; the loss
of CS and the expansion of RCA mortar (RCAM) with 25 and 50 % replacement
of NA by RCA were lower and those of the RCAM with 75 and 100 % RCA were
higher than the corresponding values of the conventional cement mortar when the
specimens were cured in a 4.24 % magnesium sulphate solution for 1 year
Fig. 5.86 Dynamic elastic modulus of RCAC containing OPC and OPC-slag binder up to
12 months exposure in a 5 % sulphate solution (Berndt 2009 )