聚乙烯醇纤维增强偏高岭土-水硬石灰砂浆材料性能的研究

Study on the property of PVA fiber reinforced metakaolin hydraulic lime mortar

针对偏高岭土-水硬石灰砂浆材料抗拉强度低、极限延伸率小、性脆的问题,为了提高其韧性和稳定性,增强其抗裂能力,设计并制备了聚乙烯醇(PVA)纤维掺杂偏高岭土-水硬石灰砂浆材料,开展了PVA纤维不同掺量、不同长度下偏高岭土-水硬石灰砂浆材料收缩率、波速、抗压强度、抗折强度及劈裂抗拉强度的试验研究,通过扫描电镜观察分析了PVA纤维在偏高岭土-水硬石灰砂浆材料中的微观作用机理。结果表明:PVA纤维改变了偏高岭土-水硬石灰砂浆的收缩率和内部结构。试样的抗折强度和劈裂抗拉强度随着纤维增加而增大,抗压强度会在纤维长度一定时随着掺量的增多而降低。PVA纤维对砂浆材料整体性有明显改善,受压后仍能够保持着较好的原样性,纤维和砂浆基体之间产生了机械铆合作用,具有较好黏结性。

Aiming at the problems of metakaolin hydraulic lime mortar material,such as low tensile strength,low ultimate elongation and brittleness,in order to improve its toughness and stability,enhance its crack resistance,the PVA fiber doped metakaolin hydraulic lime mortar material was designed and prepared.The shrinkage rate,wave velocity,compressive strength,flexural strength and splitting tensile strength of the mortar with different content and length of PVA fiber were studied.The mechanism of PVA fiber in mortar was analyzed by SEM.The results shown that PVA fiber changed the shrinkage and internal structure of the mortar.The flexural strength and splitting tensile strength increased with increasing the fiber amount.The compressive strength decreased with increasing the fiber amount when the fiber length was constant.PVA fiber can obviously improve the integrity of mortar,and kep good original condition after compression.Mechanical riveting cooperation was developed between fiber and mortar,and had good adhesion.