Epoxy resin adhesive with poor high temperature resistance is often used in retrofitted structures. To improve fire endurance of the retrofitted structures, it is helpful to use inorganic adhesive instead of epoxy resin. In this way, one kind of geopolymer, which was made at room temperature and atmospheric pressure from activated kaolin with alkali activator, is prepared in this paper to act as inorganic adhesive. The influences of calcined temperature and holding time of kaolin, concentration and modulus of sodium silicate solution, and water-binder ratio on the corapressive strength, mini-slump extension and setting time of this geopolymer are investigated by using orthogonal experiment. Test results show that when the water-binder ratio is 0. 65, the kaolin, calcined at 800℃ for 3h and activated by sodium silicate solution with a modulus of 1. 0 and a concentration of 40% , can be used to make the applicable geopolymer with properties as 3-day compressive strength of 48. SMPa, 28-day compressive strength of 51. 2MPa, mini-slump extension of 158mm, and setting time of about 2h at 15℃ and 70% relative humidity.%加固结构中,加固材料与构件表面之间通常采用高温性能很差的环氧类胶粘剂,为提高该类结构的抗火性能,改用无机类胶粘剂是有益的.为此,本文将广东产高岭土煅烧活化后加入碱性激发剂,在常温常压下制备成拟用作胶粘剂的地聚物.通过正交试验研究了高岭土煅烧温度、恒温时间、水玻璃溶液浓度、水玻璃模数、水胶比对地聚物抗压强度、净浆流动度和凝结时间的影响规律.研究表明:经800℃煅烧且恒温3h的高岭土,在浓度40％和模数1.0的水玻璃溶液激发下,水胶比为0.65时可制备出3天抗压强度48.5 MPa、28天抗压强度51.2MPa、净浆流动度158mm、温度15℃和相对湿度70％时初凝时间约2小时的地聚物,可满足实际工程需要.
展开▼
