Obviously, the addition of polypropylene fibers is significant in controlling plastic shrinkage cracks in the early stage and improving ductility for concrete at low fiber volume fraction.
低掺量的聚丙烯纤维掺入混凝土后可显著控制混凝土早期收缩裂缝，提高混凝土的耐久性。
2
The autogenous shrinkage of HPC develops greatly and mainly during early age due to a low water binder ratio, but there is no standard test method for early autogenous shrinkage of the concrete.
高性能混凝土因水胶比低、自收缩大且主要发生在早期，而目前对于早期自收缩的测量还没有统一标准可依。
3
Aiming at these defects, a kind of special mortar for plastering aerated concrete with good workability, good water retention, high bonding strength and lowshrinkage ratio has been prepared.