EXPERIMENTAL STUDY ON CAST-IN-PLACE CONCRETE FLOOR DRYING SHRINKAGE CRACK UNDER NON-LOADING

摘要

The dry shrinkage cracks will increase largely when concrete slab area is bigger in construction stage, which affects the integrity, the security and the durability of the structure seriously.And it is decreased to concrete structure component bearing capacity. An experimental program was undertaken to determine the concrete mix design which had high crack resistance and impervious ability. At the same time, the factors effecting concrete performance was researched when polypropylene textile fibre is joined in concrete. A lot of tests are carried on to study concrete performance comparing with different quantity of polypropylene textile fibre, different quantity of plumping agent, different constraints and different curing conditions by a practical project. Finally,the measure reducing shrinkage cracks of concretes is give by mechanical properties and action mechanism analysis.