Use of Preplaced Casting Method in Lightweight Aggregate Concrete

الملخص EN

This study addresses the use of preplaced casting method in lightweight aggregate concrete (LC) to provide a new perspective to solve the aggregate segregation.

In casting preplaced lightweight aggregate concrete (PLC), the lightweight aggregates are cast into formworks and then fresh grout is injected to fill voids.

PLC and conventional lightweight aggregate concrete (CLC) with three different mixtures are compared to observe the degree of segregation.

The properties of PLC and CLC are characterized by means of cubic and axial compression, splitting tension and flexural tests, static modulus of elasticity, and drying shrinkage measurements.

Results show that the mechanical properties of PLC are improved with respect to that of CLC with the same mixture.

The increase of shrinkage is approximately 13% for the CLC and 6% for PLC when w/c ratio ranges from 0.4 to 0.5 due to effect on interlocking.

PLC shows an increased tendency in elastic modulus by approximately 2.5% of 0.5 w/c ratio, 2.7% of 0.45 w/c ratio, and 3.3% of 0.4 w/c ratio at the age of 28 days compared with CLC.

In conclusion, PLC has significant reduction in the weight on the premise that it shows excellent mechanical properties.