No. Even though they appear to be similar, They are totally different products. Water Absorbtion of AAC is 200% More than that of CLC blocks. Broken blocks of CLC can be used for Sunken Filling but due to more water absorbtion in AAC it should be avoided. The CLC is cured in conventional methods and the AAC is through Steam Curing, which makes the Compressive strength final in AAC , but CLC like normal concrete strength increases over time.