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石粉对机制砂混凝土抗渗透性和抗冻融性能的影响 总被引:1,自引:0,他引:1
测试了石粉含量(质量分数)对不同强度等级机制砂混凝土强度、抗氯离子渗透性能和抗冻性能的影响.结果表明:随着机制砂中石粉含量的增加,低强度机制砂混凝土的抗氯离子渗透性能提高,而抗冻性能降低,尤其是当石粉含量高于10%(石粉与水泥体积比超过1:3.47)时,低强度机制砂混凝土抗冻性劣化明显;当石粉含量大于7%时,高强机制砂混凝土工作性劣化,而当石粉含量从3.5%提高到14%,高强机制砂混凝土的抗氯离子渗透性能和抗冻性能均未降低. 相似文献
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CMC和PAM对砂浆性能的影响 总被引:1,自引:0,他引:1
加气混凝土是一种新型建筑材料,自身具有许多优点。然而由于普通砂浆的保水性能不能适应加气混凝土的吸水性能,加气混凝土抹灰层经常出现开裂现象,这阻碍了加气混凝土的广泛应用。通过两类增稠剂CMC和PAM)对砂浆性能影响的试验研究发现,CMC可以大幅度提高砂浆的保水性能,从而可以较好地解决普通砂浆的保水性能与加气混凝土吸水性能不相适应的问题:PAM对普通砂浆的保水性能改善较少。 相似文献
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为研究激振搅拌工艺对水泥稳定煤矸石混合料性能的影响规律,以水泥稳定碎石为基准,对比分析普通搅拌与激振搅拌对不同水泥剂量的水泥稳定基层材料无侧限抗压强度的影响。结果表明:在干拌状态下增加激振工艺对基层混合料抗压强度的提升效果显著,在激振气压为0.4 MPa、激振干拌30 s后普通湿拌30 s条件下,混合料的7 d无侧限抗压强度达到最佳;激振搅拌对水泥稳定碎石、水泥稳定煤矸石混合料强度的平均提升幅度约为20%,对煤矸石混合料的强度提升更加显著,水泥剂量越少,提升幅度越大。SEM结果表明激振搅拌后混合料中的水化产物分布更加均匀,结构更加致密;经线性拟合计算,当水泥剂量为2.0%~7.0%(质量分数,下同)时,激振搅拌对于碎石混合料可节约8.9%~26.3%的水泥,对于煤矸石混合料可节约12.9%~30.8%水泥,且节约率与水泥剂量成反比。 相似文献
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王稷良 《武汉理工大学学报(材料科学英文版)》2009,24(2):321-325
The relation between methylene blue (MB) value of MS and its limestone dust content and clay content was investigated. The
effects of MB value ranging from 0.35 to 2.5 on the workability of fresh concrete and crack propagation characteristics at
the age of 24 hours, and effects on the mechanical properties, dry shrinkage of the harden concrete were tested. The experimental
results show that the MB value is not related with the limestone dust content of MS, but in direct proportion to clay content.
With the increase of MB value, the concrete workability decreases, and the flexural strength and 7 d compressive strength
reduce markedly, whearas the 28 d compressive strength is not affected. When the MB-value is less than or equal to 1.35, the
change of the MB-value has a little influence on early plastic cracking and dry shrinkage property of concrete, but when the
MB-value is more than 1.35, the tendency of plastic cracking and dry shrinkage is remarkable.
Funded by the Nationd West Communication Construction Technology Project(No.200331881106) 相似文献
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