SAP内养护混凝土抗冻性影响分析

Analysis of the Influence of Frost Resistance of Concrete Cured in SAP

在大温差环境中,混凝土常因冻融损害失去服役作用。高吸水树脂(SAP)作为内养护材料给混凝土内部提供水分,减少混凝土收缩开裂程度,进而改善混凝土抗冻性能。设计掺量为0.0%、0.2%、0.4%、0.6%、0.8%、1.0%的SAP进行内养护混凝土的成型,通过冻融循环试验、吸水率试验以及孔结构分析,以相对动弹性模量评价参数ω、质量损失率M_(S)、吸水率R_(x)以及微型气泡数来分析SAP对混凝土抗冻性的影响。结果表明:掺加SAP明显改善了混凝土抗冻性能,当最佳掺量为0.6%时,显著降低了混凝土冰冻48 h后的吸水率,微型气泡个数的增加使抗冻性能得到有效改善。

In large temperature difference environment,concrete often loses its service function because of freeze-thaw damage.As an internal curing material,super absorbent polymer(SAP)can provide water for the concrete,the degree of shrinkage and cracking can be reduced,and the frost resistance of concrete can be improved.SAP of 0.0%,0.2%,0.4%,0.6%,0.8%or 1.0%was designed to use for curing concrete.Through freeze-thaw cycle test,water absorption test and Pore Structure Analysis,the influence of SAP on frost resistance of concrete is analyzed with relative dynamic modulus of Elasticity(ω),mass loss rate(M_(S)),water absorption rate(R_(x))and number of micro-bubbles.The results showed that the Frost Resistance of concrete is obviously improved by adding SAP,and the optimum content of SAP is 0.6%.When the content of SAP is 0.6%,the water absorption of concrete after 48 hours of freezing is significantly reduced,and the frost resistance is effectively improved with the increase of the number of micro-bubbles.