Hou Yuying, Li Lin, Li Tao, Wu Qianqian, Zhou Yali, Yang Jianming
Department of Civil Engineering, Sanjiang University, Nanjing 210012, China.
China Construction Eighth Bureau Third Construction Co., Ltd., Nanjing 210012, China.
Materials (Basel). 2023 Mar 8;16(6):2183. doi: 10.3390/ma16062183.
For the repair of narrow cracks in concrete, the potassium magnesium phosphate cement (MKPC)-based material paste should have high fluidity and self-compacting ability, making it convenient for pouring and compacting. A self-compacting MKPC paste that meets the index requirements recommended by the European Federation of National Associations Representing for Concrete (EFNAFC) was prepared by increasing the water-cement ratio and adding water glass and fly ash (FA). Specimens of self-compacting MKPC paste were subjected to long-term water corrosion tests, which found that those high-fluidity MKPC paste specimens (reference sample M0) that were produced with only an increased water-cement ratio lost 15-30% of their strength. The residual ratio of folding to compression was 84.6%, and the volume expansion rate was 7.78 × 10 after immersion in water for 560 days. The strength residual rate of MKPC slurry (M1) modified by sodium silicate and fly ash is over 90% after 560 days of immersion in water, and the residual rate of flexural-compressive ratio is 101.3%, which meets the requirements of hydraulic cement-based materials. The volume expansion rate of M1 is 5.19 × 10, which is 67% of the reference sample M0 with the same water immersion age.
对于混凝土中狭窄裂缝的修复，磷酸钾镁水泥（MKPC）基材料浆体应具有高流动性和自密实能力，以便于浇筑和压实。通过提高水灰比并添加水玻璃和粉煤灰（FA），制备了一种符合欧洲混凝土国家协会联合会（EFNAFC）推荐指标要求的自密实MKPC浆体。对自密实MKPC浆体试件进行长期水腐蚀试验，结果发现，仅通过提高水灰比制备的高流动性MKPC浆体试件（参考样品M0）强度损失了15 - 30%。在水中浸泡560天后，抗折与抗压残余比为84.6%，体积膨胀率为7.78×10。用硅酸钠和粉煤灰改性的MKPC浆体（M1）在水中浸泡560天后强度残余率超过90%，抗折抗压比残余率为101.3%，满足水硬性水泥基材料的要求。M1的体积膨胀率为5.19×10，在相同浸水龄期下是参考样品M0的67%。
