Technical Points for Lightweight Aggregate Concrete Construction

The construction process for lightweight aggregate concrete is essentially the same as that for normal concrete. However, due to the low bulk density, porous structure, and high water absorption rate of the lightweight aggregates, the lightweight aggregate concrete also exhibits certain characteristics. Only by paying full attention during the construction process can the construction quality of the project be ensured.

Requirements for the Storage and Pre-wetting of Lightweight Materials

Aggregate should be stacked separately by type and particle size; mixing them can directly affect the workability, strength, and apparent density of concrete. When using natural gradation, the stacking height of lightweight aggregate should not exceed 2 meters, and precautions should be taken to prevent the admixture of leaves, soil, and other harmful substances. Preventive measures against rain should be taken during the stacking and transportation of lightweight sand.

Lightweight aggregates have a high water absorption, making it difficult to control the workability of concrete mixtures. Therefore, during construction seasons with temperatures above 5°C, pre-wetting treatment should be applied to lightweight aggregates. The pre-wetting time can be determined based on the external temperature and the natural moisture content of the incoming materials, generally requiring 12 to 24 hours of watering and pre-wetting the aggregates before drying and adding them to the mix. Below 5°C or for aggregates without open pores on the surface, pre-wetting is generally not necessary.