在未加载与加载条件下,采用快冻法研究了快速碳化28 d后的普通混凝土(Ordinary Portland Cement Con-crete,OPC)、大掺量矿物掺合料混凝土(Concrete with High Content Mineral Admixture,HCMC)以及同时掺加混杂纤维、膨胀剂、引气剂和大量矿物掺合料的绿色高耐久性混凝土(Green High Durable Concrete,GHDC)在水和10%NaCl溶液中的抗冻性。结果表明,碳化作用降低了OPC和HCMC在NaCl溶液中的抗冻性,但能够改善GHDC在NaCl溶液中的抗冻性。在NaCl溶液的化学腐蚀及其与弯曲荷载的耦合作用下,碳化OPC与碳化HCMC很快发生冻融破坏,其破坏特征并非表面剥落,而是内部微裂纹的扩展。GHDC即使发生了严重的碳化作用,在NaCl溶液、弯曲荷载与冻融循环及其耦合作用下仍然具有非常高的耐久性能。
The freezing-thawing durability of carbonized ordinary Portland cement concrete(OPC),concrete with high content mineral admixture(HCMC) and green high durable concrete(GHDC) subjected to water and 10% NaCl solution with and without loading were studied by accelerated freezing-thawing method.Results show that carbonation reduces the freezing-thawing durability of OPC and HCMC immersed NaCl solution,but it is beneficial to GHDC.When subjected to the combined action of freeze-thaw cycling,NaCl solution and flexural loads,carbonized OPC and carbonized HCMC destructed quickly,and the damage is characterized by the developing of inner cracks,not by the surface scaling.But for GHDC,although been seriously carbonized,it demonstrated very high freeze-thaw durability when subjected to the combined action of freeze-thaw cycling,NaCl solution and flexural loads.