摘要
利用造纸污泥灰和生活污泥灰替代部分水泥制备胶凝材料,研究了污泥灰掺量对污泥灰-水泥胶凝体系力学性能的影响,采用X射线衍射、红外光谱、扫描电镜和能谱分析手段对胶凝体系水化产物的矿物组成、化学结构及微观形貌进行研究。结果表明,随着污泥灰掺量增加,胶凝体系抗压强度不断降低,当污泥灰掺量超过40%,试样3 d抗压强度比小于5%。当水泥掺量一定,提高造纸污泥灰的掺加比例有利于胶凝体系早期强度的增长,生活污泥灰可有效提高试样后期强度,但掺量不宜过多。随造纸污泥灰掺量提高,水化产物中氢氧化钙和C—S—H凝胶生成量增大,氢氧化钙晶体由片状发育为板状,紧紧包裹于C—S—H凝胶层状结构中,造纸污泥灰中含有的文石型Ca CO3晶体具有较高的力学强度,可桥接于水化试样微观裂隙两侧,阻碍裂隙的扩展,进而提高胶凝体系的力学强度。
The present paper intends to make an exploration of the mineral composition,the chemical structure and micro-morphology of the hydration products of the cementitious system via the X-ray diffraction,the infrared spectroscopy,as well as via the electronic scanning microscopy and energy dispersive spectrometry.As is known,the papermaking sludge-ash and the domestic sludge-ash can be used to replace part of cement so as to make the cementitious materials,whereas the effect of the sludge-ash content on the mechanical properties of the sludge cement cementitious system has also been examined.The results of our experimental studies indicate that,on the condition when the cement content is fixed,it is beneficial to increase the early strength of the cementitious samples by increasing the proportion of the papermaking sludge-ash,and,then,the latter strength of the samples can be effectively improved by the domestic sludge-ash,though the amount should not be too large.However,when the cement content rate decreases,the compressive strength of the cementitious system should also be constantly decreased correspondingly.For example,when the sludge ash content is over 40%,the 3-rd compressive strength ratio of the sample should be dropped by no more than 5%.The hydration products of the sludge ash-cement cementitious system may include the calcium hydroxide,ettringite,calcite,aragonite and C-S-H gel.On the other hand,the said papermaking sludge ash tends to be able to accelerate the hydration of the calcium silicate in the cement and give off more calcium hydroxide and C-S-H gel,so as to be able to promote the early strength of the cementitious system.Nevertheless,the activated SiO2 within the household sludge ash may experience at the later stage of hydration,can be affected by the OH-and then produce a large amount of C-S-H gel and gelled,so as to accelerate the increase of the 28 d strength of the cementitious system.In addition,with the increase of the sludgeash content,the amount of the calcium hydroxide and C-S-H gel in
作者
卢前明
张元馨
张瑞林
孙文标
LU Qian-ming;ZHANG Yuan-xin;ZHANG Rui-lin;SUN Wen-biao(School of Safety Engineering,Henan University of Engineering,Zhengzhou 451191,China;Zhengzhou Technical College,Zhengzhou 450121,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2019年第1期308-313,共6页
Journal of Safety and Environment
基金
国家自然科学基金项目(51474094)
河南省高校重点科研项目(18A440007)
河南工程学院博士基金项目(D2017003)
关键词
环境工程学
污泥灰
微观结构
胶凝体系
力学强度
environmental engineering
sludge-ash
microstructure
cementitious system
mechanical strength
