基于界面化学理论的机制砂混凝土强度形成机理研究  

Study on strength formation mechanism of manufactured sand concrete based on interface chemistry theory

作　　者：梁鸿杰 王瑞雄 杜洪良 梁军林 容洪流[1,2,5] 颜志铭 王柳南 吴吉程 LIANG Hongjie;WANG Ruixiong;DU Hongliang;LIANG Junlin;RONG Hongliu;YAN Zhiming;WANG Liunan;WU Jicheng(School of Civil Engineering,Guangxi University,Nanning 530004,China;Key Laboratory of Engineering Disaster Prevention and Structural Safety Ministry of Education,Guangxi University,Nanning 530004,China;Guangxi Beibu Gulf Investment Group Co.,Ltd.,Nanning 530029,China;Guangxi Jiaoke Group Co.,Ltd.,Nanning 530007,China;Guangxi Special Geological Highway Safety Engineering Research Center,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004 [3]广西北部湾投资集团有限公司,广西南宁530029 [4]广西交科集团有限公司,广西南宁530007 [5]广西特殊地质公路安全工程技术研究中心,广西南宁530004

出　　处：《混凝土》2023年第12期126-130,共5页Concrete

基　　金：国家自然科学基金(51968006);广西科技创新引导项目(桂科AC16380107)。

摘　　要：为探究机制砂混凝土强度形成的机理,基于新拌混凝土屈服应力计算式并结合界面化学理论建立了适用于机制砂混凝土抗拉强度预测模型,以水泥浆含量、粗骨料用量、石粉掺量、粉煤灰掺量作为试验变量,测定了机制砂混凝土不同龄期的抗拉、抗压强度,运用预测模型分析了水泥浆含量、粗骨料用量、石粉掺量、粉煤灰掺量对机制砂混凝土强度的影响机理。结果表明:该预测模型能直观地反映了抗拉强度与固相线浓度λ、胶凝材料体积分数Vb、水泥水化程度等因素的关系,能较好地分析机制砂混凝土强度形成机理。不同配合比的机制砂混凝土强度均随着龄期增长而增大,且强度增长规律与水泥水化程度增长规律基本一致。同一水胶比下,机制砂混凝土抗拉、抗压强度随着水泥用量增加而增大,水泥用量达到450 kg/m^(3)后,增长趋势趋于平缓;当粗集料用量小于1100 kg/m^(3),粗骨料用量对强度无明显影响,粗骨料用量超过1100 kg/m^(3)后,强度明显下降;机制砂混凝土的强度均随着石粉和粉煤灰的掺量增加而减小。In order to explore the formation mechanism of the strength of manufactured sand concrete based on the yield stress calculation formula of fresh concrete and interfacial chemistry theory,a tensile strength prediction model for manufactured sand concrete was established.The tensile and compressive strength of manufactured sand concrete at different ages were measured with cement slurry content,coarse aggregate content,stone powder content and fly ash content as test variables.The influence mechanism of cement slurry content,coarse aggregate content,stone powder content and fly ash content on the strength of manufactured sand concrete was analyzed by using the prediction model.The results show that the prediction model can intuitively reflect the relationship between tensile strength and solid line concentration,cementitious material volume fraction,cement hydration degree,and can better analyze the strength formation mechanism of manufactured sand concrete.The strength of manufactured sand concrete with different mix proportions increases with age,and the strength growth law is basically consistent with the growth law of cement hydration degree.Under the same water-cement ratio,the tensile strength and compressive strength of manufactured sand concrete increase with the increase of cement slurry dosage.When the cement dosage reaches 450 kg/m^(3),the growth trend tends to be gentle.When the amount of coarse aggregate is less than 1100 kg/m^(3),the amount of coarse aggregate has no significant effect on the strength.When the amount of coarse aggregate exceeds 1100 kg/m^(3),the strength decreases significantly.The strength of manufactured sand concrete decreases with the increase of stone powder and fly ash.

关 键 词：机制砂混凝土 抗拉强度 预测模型 

分 类 号：TU528.041[建筑科学—建筑技术科学]