乳化沥青对PVA纤维增强水泥基复合材料韧性的影响

Effect of Asphalt Emulsion on the Toughness of PVA Fiber Reinforced Cementitious Composites

为了研究乳化沥青对纤维增强水泥基复合材料韧性的影响,采用乳化沥青制备PVA纤维增强水泥基复合材料,对其强度和韧性性能进行测试,并采用SEM对试件断面微观形貌进行了分析。结果表明,加入乳化沥青以后,复合材料的抗压强度和抗折强度迅速下降,而韧性性能迅速上升;纤维的破坏模式由拉断破坏变成拔出破坏,随之在试件底部出现了多缝开裂;当乳化沥青用量为10%时,试件出现了明显应变硬化现象;当乳化沥青用量过大时,韧性反而下降。此外,结合微观力学原理,对乳化沥青的增韧机理进行了阐述。

This paper was conducted on the effect of asphalt emulsion on the toughness of PVA fiber reinforced cementitious composites.Asphalt emulsion was adopted to prepare PVA fiber reinforced cementitious composites and the tests of strength and toughness performances of these materials were carried out.The micromorphology of the fracture surface for specimens was analyzed using SEM.The results show that the asphalt emulsion can decrease the compressive and flexural strength of cementitious composites.With the addition of asphalt,the toughness increases sharply.The failure mode of fiber changes from fracture failure into pull-out failure and causes multiple cracking at the bottom of specimens.The strain hardening behavior can be achieved when the addition of asphalt emulsion is 10%.However,the toughness tends to slow with the excessive addition of asphalt emulsion.At last,the toughening theory of asphalt emulsion on cementitious composites was analyzed on the basis of micromechanics principles.