输水隧洞混凝土表面喷涂丙乳净浆性能及其应用研究

Performance and Application of Spraying Acrylic Emulsion Cement Paste on Concrete Surface of Water Conveyance Tunnel

为探究丙乳净浆在输水建筑物混凝土表面防护的适用性,以聚灰比和乳液浓度为变量因素,分析丙乳净浆流动度、抗拉强度、抗压强度和抗折强度的变化规律,通过层间黏结强度试验分析丙乳净浆的可操作时间,最终获得用于喷涂施工的丙乳净浆配比。研究结果表明,丙乳净浆流动度随着聚灰比的减小而减小,随着乳液浓度的降低呈现先增大后减小的特征。随着乳液浓度的降低,丙乳净浆抗压强度强度升高,抗拉和抗着强度降低。通过压拉强度比发现,乳液浓度的提高可增加丙乳净浆的韧性。丙乳净浆层间黏结强度随着浇筑时间间隔的延长而降低,建议施工间隔不超过1 h。实际工程应用表明,采用丙乳净浆进行隧洞表面防护可以增强混凝土基体,并且形成很高的黏结强度,可为类似混凝土表面防护提供参考。

In order to explore the applicability of acrylic emulsion cement paste in concrete surface protection of water conveyance structures,the fluidity,tensile strength,compressive strength,and flexural strength of acrylic emulsion cement paste were analyzed by taking aggregate-cement ratio and emulsion concentration as variable factors,and the operable time of acrylic emulsion cement paste was analyzed by interlaminar bonding strength test.Finally,the ratio of acrylic emulsion cement paste for spraying construction was obtained.The results show that the fluidity of acrylic emulsion cement paste decreases with the decrease in aggregate-ash ratio and increases first and then decreases with the decrease in emulsion concentration.With the decrease in emulsion concentration,the compressive strength of acrylic emulsion cement paste increases,while the tensile strength and anti-sticking strength decrease.Through the ratio of compressive strength to tensile strength,it is found that the increase in emulsion concentration can increase the toughness of acrylic emulsion cement paste.The interlaminar bond strength of acrylic emulsion cement paste decreases with the extension of the pouring time interval,so it is recommended that the construction interval should not exceed 1 h.The practical application shows that the concrete matrix can be strengthened,and the high bonding strength can be formed by using acrylic emulsion cement paste for tunnel surface protection,which can provide a reference for similar concrete surface protection.