Assessment of recycling use of GFRP powder as replacement of fly ash in geopolymer paste and concrete at ambient and high temperatures
Assessment of recycling use of GFRP powder as replacement of fly ash in geopolymer paste and concrete at ambient and high temperatures
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DOI：
10.1016/j.ceramint.2022.01.293
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发表时间：
2022-01
影响因子：
5.2
通讯作者：
Jun Wang;Chujing Zheng;L. Mo;H. Gangarao;Ruifeng Liang
中科院分区：
文献类型：
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作者：
Jun Wang;Chujing Zheng;L. Mo;H. Gangarao;Ruifeng Liang
玻璃纤维增强聚合物（GFRP）废弃物引起的环境问题已引起广泛关注。因此，开发具有成本效益的玻璃钢复合材料废物回收和再利用方法至关重要。在本研究中，GFRP废粉末替代物的配方设定为20-40重量%。通过将玻璃钢粉末、粉煤灰（FA）、钢渣（SS）和普通波特兰水泥（OPC）与钠基碱激发剂混合形成地质聚合物。研究了玻璃钢粉含量、激发剂浓度、液固比和激发剂溶液模量对地聚合物混合物物理力学性能的影响。基于28天的抗压强度，地质聚合物混合物的最佳组合被确定为30wt%GFRP粉末含量、85%的活化剂浓度、0.65的L/S和1.3的活化剂溶液模量。GFRP粉末/FA基地质聚合物的压缩强度与弯曲强度的比率显著低于FA/钢渣基地质聚合物的压缩强度与弯曲强度的比率，这表明GFRP粉末的掺入改善了地质聚合物的脆性。在地聚合物混凝土中掺入30%的GFRP粉取代FA，可使地聚合物混凝土的抗压和抗折强度提高28%。在暴露于600 °C后，含有30wt%GFRP粉末的地质聚合物混凝土的弯曲强度损失小于不含GFRP粉末的试样的弯曲强度损失。暴露于900 °C后，含有30wt%GFRP粉末的地质聚合物混凝土的抗压强度和抗弯强度损失与不含GFRP粉末的试样的抗压强度和抗弯强度损失相似。所开发的GFRP粉末/FA基地质聚合物表现出与FA基地质聚合物相当或上级的物理机械性能，因此作为建筑材料提供了很高的应用潜力。
Environmental issues caused by glass fiber reinforced polymer (GFRP) waste have attracted much attention. The development of cost-effective recycling and reuse methods for GFRP composite wastes is therefore essential. In this study, the formulation of the GFRP waste powder replacement was set at 20–40 wt%. The geopolymer was formed by mixing GFRP powder, fly ash (FA), steel slag (SS) and ordinary Portland cement (OPC) with a sodium-based alkali activator. The effects of GFRP powder content, activator concentration, liquid to solid (L/S) ratio, and activator solution modulus on the physico-mechanical properties of geopolymer mixtures were identified. Based on the 28-day compressive strength, the optimal combination of the geopolymer mixture was determined to be 30 wt% GFRP powder content, an activator concentration of 85%, L/S of 0.65, and an activator solution modulus of 1.3. The ratios of compressive strength to flexural strength of the GFRP powder/FA-based geopolymers were considerably lower than those of the FA/steel slag-based geopolymers, which indicates that the incorporation of GFRP powder improved the geopolymer brittleness. The incorporation of 30% GFRP powder in geopolymer concrete to replace FA can enhance the compressive and flexural strengths of geopolymer concrete by 28%. After exposure to 600 °C, the flexural strength loss for geopolymer concretes containing 30 wt% GFRP powder was less than that of specimens without GFRP powder. After exposure to 900 °C, the compressive strength and flexural strength losses of geopolymer concretes containing 30 wt% GFRP powder were similar to those of specimens without GFRP powder. The developed GFRP powder/FA-based geopolymers exhibited comparable or superior physico-mechanical properties to those of the FA-based geopolymers, and thus offer a high application potential as building construction material.