摘要
为有效抑制混合梁桥用混凝土的收缩,研发混合梁桥水泥基材料的新型掺合料。将白云石与污泥分别按质量比为1∶2、1∶1和2∶1混合后,经过800℃煅烧0.5 h制备得到煅烧白云石—污泥。分析煅烧白云石—污泥对复合水泥的水化反应、力学性能和体积稳定性的影响规律,并通过分析复合水泥浆体的产物组成阐明其影响机理。结果表明,煅烧白云石—污泥会延缓复合水泥的水化放热反应,降低早期强度,但提高后期强度。而且,当煅烧白云石—污泥中白云石和污泥比例为1∶2时,复合水泥砂浆60 d强度最高。煅烧白云石—污泥成分中的偏高岭土具有火山灰活性,而且矿物组成中的CaCO3和白云石还会与水泥中的铝酸三钙反应成碳铝酸盐,从而提高强度;煅烧白云石—污泥中氧化镁的水化还会引起复合水泥的膨胀。
In order to effectively inhibit the shrinkage of concrete for hybrid girder bridges,a new admixture of cementbased materials for hybrid girder bridges was developed.Calcined dolomite-sludge was prepared by calcining dolomite and sludge at 800℃for 0.5 h after mixing them at mass ratios of 1∶2,1∶1 and 2∶1,respectively.The effects of calcined dolomitesludge on the hydration reaction,mechanical properties and volume stability of composite cement were analyzed,and the influence mechanism was clarified by analyzing the product composition of composite cement paste.The results show that calcined dolomite-sludge can delay the hydration exothermic reaction of composite cement,reduce the early strength,but improve the later strength.Moreover,when the ratio of dolomite to sludge in calcined dolomite-sludge is 1∶2,the strength of composite cement mortar is the highest at 60 d.The metakaolin in the calcined dolomite-sludge composition has pozzolanic activity,and the CaCO3 and dolomite in the mineral composition also react with the tricalcium aluminate in the cement to form carbon aluminate,thereby improving the strength.The hydration of magnesium oxide in calcined dolomite-sludge also causes the expansion of composite cement.
作者
尚雪仁
王文科
唐亮
翟晓亮
SHANG Xueren;WANG Wenke;TANG Liang;ZHAI Xiaoliang(CCCC First Harbor Engineering Co.,Ltd.,Tianjin 300450,China;CCCC First Highway Consultants Co.,Ltd.,Xi'an 710065,China)
出处
《金属矿山》
北大核心
2025年第8期315-320,共6页
Metal Mine
基金
陕西省交通厅交通科技项目(编号:20-40K)。
关键词
煅烧白云石—污泥
水化反应
强度
水泥基材料
calcined dolomite-sludge
hydration reaction
intensity
cement-based materials
