Influence of lightweight aggregate on shrinkage reducing efficiency of concrete

The autogenous shrinkage at early age and drying shrinkage of lightweight aggregate concrete with different mix proportions were measured, and the influence of lightweight aggregate in concrete on the shrinkage reduction efficiency due to internal cu-ring was studied. The results indicate that the absorption-desorption rate and the degree of pre-wetting of ceramsite have a significant impact on the shrinkage reduction efficiency of concrete. With the increase of pre-wetting of ceramsite, the autogenous shrinkage of high performance lightweight concrete decreases, and the shrinkage reduction efficiency improves; it is about 39.1% for the saturated Binxian ceramsite. The ceramsite sand has a similar effect; it has greater shrinkage reduction efficiency, which reached 95.6% for the saturated ceramsite sand at the dosage of 130 kg/m³.