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CONCRETE TECHNOLOGY20 CPI %u2013 Concrete Plant International | India Edition %u2013 6 | 2025 www.cpi-worldwide.comit can be noted that the LC3 mixes with B-Clay and PH-Clay generally have lower shrinkage strain than the reference mixes. The LC3 mixes with H-Clay (regardless of the clinker content) show higher shrinkage strain compared to the reference mixes, especially up to about 80 days.It is usually assumed that it is mainly the w/b ratio (not the binder system) that controls shrinkage development in concrete. However, especially in the case of clays, it is hypothesised that the available water to react in the system initially is affected by the internal surface area (ISA) of the clay. This means that a clay that has high ISA most likely will absorb more of the available water in the system which in turn reduces the rate of loss of moisture in the paste. This explains the low shrinkage strain in the LC3 mixes with B-Clay and PHClay, compared to the reference mixes. A similar trend is also observed in the case of concrete mixes with 0.55 w/b ratio (Fig. 6). In this case the HC-Clay has higher ISA than the B-Clay, but the LC3-55(HC:35/10) appears to have higher shrinkage strain compared to LC3-55(B:35/10) which might be attributed to the higher dosage of SP (2%) in this mix compared to 1.2% in the LC3-55(B:35/10). Fig. 5: Shrinkage strain development (w/b = 0.4).Fig. 6: Shrinkage strain development (w/b = 0.55).