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利用XRD层析法和SEM研究了集料与硅酸盐水泥石界面区的组成、CH晶体取向指数等。实验结果表明,界面区中水化产物主要是C-S-H凝胶、CH晶体、AFt、孔隙以及未水化的熟料矿物;界面区中CH晶体发育良好,取向作用较强,界面处它以(001)面平行于集料表面生长;水化龄期增长或水灰比提高时,CH晶体取向作用增强,而且水灰比高时,界面区中孔洞、裂纹增多,降低界面粘结强度;水泥中掺入5.0%wt硅灰后,CH晶体取向作用下降;水泥中掺入5.0wt%FDN减水剂,由于水泥早期水化程度低,对水泥石-集料早期粘结强度不利,但28d后其粘结强度就能赶上并超过其它试样。
The composition of the interface region between the aggregate and the Portland Cement Paste, CH crystal orientation index, etc. were studied by XRD and SEM. The experimental results show that the hydration products in the interfacial zone are mainly CSH gels, CH crystals, AFt, pores, and unhydrated clinker minerals; CH crystals in the interfacial zone are well-developed and have a strong orientation effect. The surface is parallel to the surface of the aggregate; when the age of hydration increases or the ratio of water to cement increases, the crystal orientation of CH increases, and when the ratio of water to cement is high, the pores and cracks in the interface area increase and the interfacial bond strength decreases; With the addition of 5.0%wt silica fume, the orientation of CH crystals decreased. The addition of 5.0wt% FDN water reducer in cement resulted in poor early hydration of the cement, which was unfavorable to the early bond strength of the cement stone-aggregate, but after 28d Its bond strength can catch up and exceed other specimens.