矿物掺和料对水泥浆体流变性能的影响

将几种活性和非活性矿物掺和料对水泥浆体流变性能的影响作对比试验,试验结果表明:矿物掺和 料的加入不改变水泥浆体的流变类型,但各种矿物掺和料的加入在一定程度上改变了水泥浆体的流变参数。     

Relationships between modified methylene blue value of microfines in manufactured sand and concrete properties

To better understand and assess the effect of microfines on concrete properties, the synergetic effect of methylene blue value and content of microfines on properties of low and high strength concrete was studied and then the relationships between the index of modified methylene blue value (MMBV) and concrete properties were investigated. The results show that relationships between MMBV and fresh and hardened properties of concrete can be fully established, and the correlation between MMBV and C60 concrete property is higher than the correlation between MMBV and C30 concrete. With the increase of MMBV, concrete workability and frost resistance decrease while drying shrinkage decreases; however, compressive strength and chloride-ion penetration resistance of C30 concrete have not been negatively affected whereas those of C60 concrete are significantly deteriorated when MMBV exceeds 100. To make use of microfines without remarkably damaging concrete quality, it is suggested that MMBV of microfines in MS used in C30 and C60 concrete be no more than 100.     

石粉对水泥浆密实度的影响

石粉对水泥硬化的影响,可归结为化学效应和物理效应。以研究石粉的物理效应机理为出发点,在测试石粉对水泥湿堆积密度影响的基础上,通过公式计算可得在不同石粉与水泥比例时,粉体混合物密实度的变化,并采用Marsh筒法进行了验证。试验结果表明,在获得最大密实度时,不同岩性石粉与水泥的比例分别为:石灰岩石粉为10%,石英岩石粉和花岗岩石粉为5%。这对揭示石粉的物理填充效应和指导石粉做掺和料时的掺入比例具有重要的意义。     

掺有阳离子化合物的MDF水泥基复合材料的研究

利用水化热分析、 Ｆ Ｔ Ｉ Ｒ光谱技术和定量 Ｘ Ｒ Ｄ探讨了 Ｈ Ａ Ｃ／ Ｐ Ｖ Ａ 基 Ｍ Ｄ Ｆ复合材料体系中掺入阳离子对聚合物交联反应和水泥水化反应程度的影响。研究结果表明,阳离子交联聚合物凝胶的性能特性决定了 Ｍ Ｄ Ｆ复合材料的加工与力学行为。     

水泥混凝土桥面破损原因及预防处理技术

水泥混凝土桥面铺装层破损是非常普遍的问题。通过对一些高等级公路中损坏的桥面铺装层进行现场勘测 ,发现桥面铺装层破损的原因主要有 :粘结不利、桥面局部有错台出现、桥面铺装层受力不均匀、铺装材料选择不当、施工不够重视、桥面铺装层混凝土养护较差等。为此 ,提出了需采取的技术措施有 :加强桥面铺装层与桥面板之间的粘结、提高桥面铺装层混凝土的性能、严格施工工艺、加强管理并注重养护     

高强机制砂混凝土中石粉与粉煤灰的复合效应

以C60机制砂混凝土为试验对象，对比研究了3．5％、7％、10．5％、14％（质量分数）4个不同石粉掺量下分别选择不同粉煤灰（FA）掺量（0、11％、17％）配制的机制砂混凝土的工作性、强度、干缩以及耐久性．结果表明，在耐久性满足要求的前提下，11％掺量的粉煤灰与7％含量的石粉产生了良好的复合叠加效应，使混凝土获得了最佳和易性和强度值，且对干缩起到了一定的抑制作用。     

电阻率法研究磷及石灰对水泥凝结硬化的影响

用非接触式电阻率测试仪研究了不同含量的可溶磷及石灰对水泥早期水化过程中电阻率的影响。结果表明:可溶磷使得水泥早期的电阻率降低,水化进程推迟,且随着可溶磷含量的增加,电阻率呈逐步降低趋势;单独添加石灰对水泥早期水化影响较小;石灰中和可溶磷后可补偿可溶磷的对水化的延期危害,其电导率随时间变化规律与未添加磷、石灰的水泥基本一致。     

高水速凝固结材料性能和硬化机理研究

研究了高水材料性能的影响因素。运用ＸＲＤ、ＴＧ－ＤＴＡ、ＳＥＭ等研究了高水材料的水化和硬化机理。分析了石膏、生石灰等对高水材料性能影响的机理,以及非结合水在高水材料硬化浆体结构中的作用。     

高水速凝固结材料性能和硬化机理研究

研究了高水材料性能的影响因素。运用ＸＲＤ、ＴＧ－ＤＴＡ、ＳＥＭ等研究了高水材料的水化和硬化机理,分析了石膏、生石灰等对高水材料性能影响的机理,以及非结合水在高水材料硬化浆体结构中的作用。     

EFFECT OF STONE POWDER ON STONE CHIPPINGS CONCRETE

In this paper,the effect and mechanism of calcareous stone powder with size less than 0. 074mm are investigated in stone chippings concrete. The results show that the stone powder can participate in hydration reaction and acts as crystal nucleus in hydration process, namely. it has hydration activity to an extent. The strength of stone chippings concrete is enhanced and the easy-mixing capacity of the concrete mortar is modified when stone chippings contain a proper amount of stone powder. The stone powder has little effect on the wearability of the concrete.