纤维织物增强磷酸钾镁水泥基复合材料加固缺陷梁抗弯性能研究及技术应用

发布时间：2018-02-26 00:16

  本文关键词： MKPC砂浆 织物网 界面粘结 加固 抗弯性能　出处：《苏州科技学院》2015年硕士论文　论文类型：学位论文

【摘要】：磷酸钾镁水泥(MKPC)是一种早强快硬的新型胶凝材料,与普通硅酸盐水泥相比,MKPC具有低温凝结快、粘结强度高、干缩小、耐磨性和抗冻性良好等优点。本文通过进行MKPC水泥基复合材料(该文均为“MKPC砂浆”)与老混凝土界面粘结性能、纤维织物增强MKPC砂浆薄板拉伸和弯曲性能以及纤维织物增强MKPC砂浆加固两种缺陷梁的抗弯试验得出如下结论:(1)MKPC砂浆与老混凝土之间的界面粘结抗剪性能以人工凿槽时最佳;采用的新型加筋MKPC水泥净浆销栓对MKPC砂浆加固层与老混凝土之间的抗剪强度提高效果相对显著;使用混合粗砂的MKPC加固层可以提高新老混凝土之间的粘结抗拉性能,而界面剂对MKPC砂浆与老混凝土界面粘结抗拉的增强效果不明显。(2)短切玻璃纤维增强MKPC砂浆薄板拉伸强度效果要比玄武岩纤维好,且耐老化腐蚀能力会得到改善;纤维织物复合增强MKPC砂浆不仅能提高薄板弯曲承载力还起到了增韧的效果,且经过80℃水温老化后的玻璃纤维织物网不会腐蚀,仅基体强度有所降低。(3)对两种不同缺陷梁(第一种为1根对比梁,2根一次受力损伤后加固梁;第二种为1根对比梁,2根钢筋锈蚀后加固梁)进行抗弯试验研究,试验梁在损伤40%初裂后卸载进行纤维、织物增强MKPC砂浆加固的极限承载力仍有较大幅度的提高,但是加固层长度如果过短可能会发生剪切破坏;试验梁在进行钢筋通电加速锈蚀(锈蚀率5%左右)后进行纤维MKPC砂浆和纤维、织物复合增强MKPC纤维砂浆对比加固可以发现两者对于梁体极限承载能力都有所提升,但增铺织物网后的加固层刚度和延性得到提高,不会发生直接剥落现象。此次研究工作将推动MKPC在加固工程中的应用,在提升MKPC复合材料的应用技术水平;促进新材料、新技术在工程中的开发;推动建设工程科技进步等方面都具有积极的意义。
[Abstract]:Potassium magnesium Phosphate cement (MKPC) is a new type of cementing material with early strength and quick hardening. Compared with ordinary Portland cement, MKPC has the advantages of fast condensation at low temperature, high bond strength and dry shrinkage. In this paper, the interface bond properties of MKPC cement matrix composites (all "MKPC mortar") with old concrete are studied. The tensile and bending properties of fiber fabric reinforced MKPC mortar sheet and the flexural test of two kinds of defective beams strengthened by fiber fabric reinforced MKPC mortar are as follows: (1) the interfacial bond shear resistance between MKPC mortar and old concrete is the best when artificial chiseling is the best; The new reinforced MKPC cement paste pin bolt can improve the shear strength between the MKPC mortar reinforced layer and the old concrete, and the MKPC strengthened layer with mixed coarse sand can improve the bond tensile performance between the new and old concrete. The tensile strength of short cut glass fiber reinforced MKPC mortar sheet is better than that of basalt fiber, and the aging corrosion resistance will be improved. Fiber fabric composite reinforced MKPC mortar can not only improve the bending capacity of thin plate, but also toughen the glass fiber fabric net after 80 鈩，

本文编号：1535743