高掺量粉煤灰和矿渣高强混凝土抗渗性和抗冻性试验  

Experiment on anti-permeability and frost resistance of high strength concrete with high-ratio of fly ash and slag

作　　者：秦力[1] 丁婧楠 朱劲松[2] 

机构地区：[1]东北电力大学建筑工程学院,吉林132012 [2]天津大学建筑工程学院,天津300072

出　　处：《农业工程学报》2017年第6期133-139,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助(51178305;51578370);东北电力大学研究生创新基金资助(Y2015025)

摘　　要：采用粉煤灰和矿渣2种掺合料的40%和50%2种质量比例掺量,制备了高掺合料C50高强混凝土,并利用扫描电镜和X射线衍射技术分析了高比例掺合料对高强混凝土强度的影响,最后通过抗氯离子渗透试验和快速冻融试验综合分析了高掺合料C50高强混凝土的耐久性。结果表明:当复掺掺合料总质量占胶凝材料总质量的50%时,随着粉煤灰与矿渣掺入量比值的减小混凝土养护28 d强度有所增加;在掺合料总质量不变的情况下,混凝土的抗冻性和抗氯离子渗透性能均随着粉煤灰掺入量的增加和矿渣掺入量的减小而逐渐提升,但掺合料总质量的增加会降低抗氯离子渗透性能;采用抗冻耐久性指数与电通量的比值法可较好的综合评价高掺合料高强混凝土的耐久性,耐久性较好的适宜配合比为掺合料总量50%,粉煤灰与矿渣掺量比为4:1。研究可为高掺量粉煤灰和矿渣在高强混凝土中的应用提供依据,同时达到提高高强混凝土的经济性和节约资源的目的。As civil engineering develops toward high rise,large span,heavy load and lightweight structure,higher requirements in strength and performance of concrete has been put forward.Mineral admixture as the fifth component of concrete is gaining popularity in practical application and helps to improve the strength and durability of concrete.At present,researches are mainly focus on the kind of mineral admixture and its influence on concrete performance.Application of an amount of admixture is an important developing direction of high strength concrete.We prepared 2 kinds of high strength concrete containing 40%and 50%fly ash and slag respectively to identify the best quality proportion of mineral admixture in high strength concrete C50.Microstructures in different ages and phase in early age were observed with scanning electron microscopy and X-ray diffraction respectively so as to evaluate the influence of high quality proportion of admixture on high strength concrete from a microscopic perspective.Durability was assessed through chloride-ion penetration resistant test and rapid freezing-thawing test.And the comprehensive capability to resist frost and chloride ion permeation was reflected by the ratio of frost-resistant durability coefficient to electric flux value.The results showed that mineral admixture reduced the early hydration of cement.Peak value of calcium hydroxide was lower in the concrete with mineral admixture than that in the reference concrete,which led to the decrease in early strength of the concrete.Due to the super-composite effect of fly ash and slag,the later strength increased more rapidly and the structure became more compact,with some samples reaching or exceeding the reference concrete strength after 28 d curing.The strength would continue to improve in the long run.With the decline of the ratio of fly ash to slag,the strength of concrete after 28 d curing with 40%admixture decreased,while that of concrete with 50% admixture increased.Capability to resist chloride ion permeation improved as t

关 键 词：粉煤灰 矿渣 混凝土 微观结构 氯离子渗透 抗冻性 

分 类 号：TU528.0[建筑科学—建筑技术科学]