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硅酸盐通报 ›› 2023, Vol. 42 ›› Issue (1): 239-247.

所属专题: 资源综合利用

• 资源综合利用 • 上一篇    下一篇

地聚物橡胶混凝土的力学、抗冲击性能及强度机理分析

杨鹏辉, 姚远   

  1. 河南交投商罗高速公路有限公司,郑州 450000
  • 收稿日期:2022-07-25 修订日期:2022-10-12 出版日期:2023-01-15 发布日期:2023-02-15
  • 作者简介:杨鹏辉(1986—),男,高级工程师。主要从事高速公路建设管理工作。E-mail:595071231@qq.com

Analysis of Mechanical Properties, Impact Resistance and Strength Mechanism of Geopolymer Rubber Concrete

YANG Penghui, YAO Yuan   

  1. HNTIG Shangluo Expressway Co., Ltd., Zhengzhou 450000, China
  • Received:2022-07-25 Revised:2022-10-12 Online:2023-01-15 Published:2023-02-15

摘要: 为探究橡胶再生集料在地聚物混凝土中的增韧作用,采用不同比例的橡胶再生集料(粒径为0.15~0.3 mm和1~4 mm)代替地聚物混凝土中的普通集料。首先,采用工业废渣中粒化高炉矿渣粉为原料,水玻璃溶液和NaOH为激发剂制备地聚物胶凝材料,并与普通集料、橡胶再生集料混合制备地聚物橡胶混凝土;然后对地聚物橡胶混凝土的力学性能、抗冲击性能和强度机理进行探究。结果表明:添加适量比例的橡胶再生集料可提高地聚物混凝土的抗压强度,增幅为5%左右,这与橡胶再生集料表面在NaOH碱环境中的氧化和降解作用有关;但地聚物橡胶混凝土在劈裂荷载和弯曲荷载下易断裂,劈裂抗拉强度和抗折强度降低20%~30%,这是地聚物橡胶混凝土的典型特点。通过落锤冲击试验和弯拉冲击试验可知,橡胶再生集料能大幅提高地聚物混凝土的抗冲击性能,最高增幅超过200%。这是由于橡胶再生集料具有的柔性和弹性特征吸收了部分冲击能量,同时延缓了冲击荷载下混凝土初始开裂到失效破坏过程,减少了裂缝开裂应力集中,提高了地聚物混凝土的延性。在地聚物碱性条件下,橡胶颗粒表面发生氧化和降解作用,表面变得粗糙,与地聚物基体结合紧密;橡胶表面在NaOH作用下,产生羟基、羧基等亲水基团,有利于水化产物在橡胶再生集料表面附着。

关键词: 地聚物混凝土, 橡胶再生集料, 力学性能, 抗冲击性能, 固体废物

Abstract: In order to explore the toughening effect of recycled rubber aggregate in geopolymer concrete, different proportion of recycled rubber aggregate (particle size 0.15~0.3 mm and 1~4 mm) was used to replace the natural aggregate in geopolymer concrete. Firstly, geopolymer cementitious material was prepared with granulated blast furnace slag powder as raw material, sodium silicate solution and NaOH as activators, and combined with natural aggregate and recycled rubber aggregate to prepare geopolymer rubber concrete. Then the mechanical properties, impact resistance and strength mechanism of geopolymer rubber concrete were studied. The results show that the compressive strength of geopolymer concrete can be improved with an increase of about 5% by adding an appropriate proportion of recycled rubber aggregate, which is related to the oxidation and degradation of recycled rubber aggregate surface in NaOH alkali environment. However, geopolymer rubber concrete is easy to fracture under indirect tensile load and bending load, and the indirect tensile strength and flexural strength are reduced by 20%~30%, which is a typical feature of geopolymer rubber concrete. In drop hammer impact test and flexural tensile impact test, recycled rubber aggregate can greatly improve the impact resistance of geopolymer concrete with the maximum increase up to more than 200%. It is due to the flexible and elastic characteristic of recycled rubber aggregate, which absorbs some impact energy. At the same time, recycled rubber aggregate also delays the process from initial cracking to failure of concrete under impact load, reduces the stress concentration of crack cracking, and improves the ductility of geopolymer concrete. Under the alkaline condition of geopolymer, the surface of rubber particles is oxidized and degraded, and the surface becomes rough and closely combines with geopolymer matrix. Under the action of NaOH, hydrophilic groups such as hydroxyl and carboxyl groups are produced on the rubber surface, which is conducive to the adhesion of hydration products on the surface of recycled rubber aggregate.

Key words: geopolymer concrete, recycled rubber aggregate, mechanical property, impact resistance, solid waste

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