1、細度
細(xi)度(du)(du)是(shi)指(zhi)水(shui)(shui)泥顆粒的(de)粗細(xi)程度(du)(du)。水(shui)(shui)泥顆粒愈細(xi),與(yu)水(shui)(shui)起反(fan)應(ying)(ying)的(de)表面積就(jiu)愈大,水(shui)(shui)化較(jiao)快且較(jiao)完全,因而凝結硬化快,早期強度(du)(du)高(gao),但(dan)早期放熱量(liang)和(he)硬化收縮較(jiao)大,且成(cheng)本較(jiao),儲存期較(jiao)短(duan)。因此,水(shui)(shui)泥的(de)細(xi)度(du)(du)應(ying)(ying)適中。
2、凝結時間
水(shui)(shui)泥的(de)(de)凝(ning)(ning)(ning)(ning)結時(shi)(shi)間(jian)(jian)分(fen)初(chu)(chu)(chu)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)和終(zhong)(zhong)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)。初(chu)(chu)(chu)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)是(shi)從(cong)水(shui)(shui)泥加水(shui)(shui)拌合起至(zhi)水(shui)(shui)泥漿開始(shi)失(shi)去(qu)可(ke)塑性(xing)所(suo)需(xu)的(de)(de)時(shi)(shi)間(jian)(jian);終(zhong)(zhong)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)是(shi)從(cong)水(shui)(shui)泥加水(shui)(shui)拌合起至(zhi)水(shui)(shui)泥漿完(wan)全失(shi)去(qu)可(ke)塑性(xing)并開始(shi)產生強度所(suo)需(xu)的(de)(de)時(shi)(shi)間(jian)(jian)。水(shui)(shui)泥的(de)(de)凝(ning)(ning)(ning)(ning)結時(shi)(shi)間(jian)(jian)在施工中具有重要意義(yi)。為(wei)了保證有足夠的(de)(de)時(shi)(shi)間(jian)(jian)在初(chu)(chu)(chu)凝(ning)(ning)(ning)(ning)之前完(wan)成混凝(ning)(ning)(ning)(ning)土的(de)(de)攪拌、運輸和澆(jiao)搗及砂漿的(de)(de)粉刷、砌筑等施工工序,初(chu)(chu)(chu)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)不宜過短;為(wei)使(shi)混凝(ning)(ning)(ning)(ning)土、砂漿能盡快地硬化達到(dao)一定(ding)(ding)的(de)(de)強度,以利于下道工序及早進行,終(zhong)(zhong)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)也不宜過長。國(guo)家標準規定(ding)(ding),六大常用水(shui)(shui)泥的(de)(de)初(chu)(chu)(chu)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)均不得短于45min,硅酸(suan)鹽水(shui)(shui)泥的(de)(de)終(zhong)(zhong)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)不得長于6.5h,其他(ta)五類(lei)常用水(shui)(shui)泥的(de)(de)終(zhong)(zhong)凝(ning)(ning)(ning)(ning)時(shi)(shi)間(jian)(jian)不得長于10h。
3、體積安定性
水泥(ni)的體(ti)積(ji)安定性是指水泥(ni)在凝(ning)結硬化(hua)過程中,體(ti)積(ji)變化(hua)的均(jun)勻性。如(ru)果水泥(ni)硬化(hua)后產(chan)生不均(jun)勻的體(ti)積(ji)變化(hua),即(ji)所謂體(ti)積(ji)安定性不良,就會使(shi)混凝(ning)土構件(jian)產(chan)生膨脹性裂縫,降低建筑(zhu)工(gong)程質量,甚至引起嚴重事(shi)故。因(yin)此,施工(gong)中必須使(shi)用安定性合格的水泥(ni)。
4、強度及強度等級
國家標準規(gui)定(ding)(ding)(ding),采(cai)用(yong)膠砂法來測(ce)定(ding)(ding)(ding)水泥的(de)(de)(de)強(qiang)(qiang)度(du)。該法是(shi)將水泥和標準砂按(an)(an)1:3混合,加入規(gui)定(ding)(ding)(ding)數量(liang)的(de)(de)(de)水,按(an)(an)規(gui)定(ding)(ding)(ding)的(de)(de)(de)方法制成試件,并按(an)(an)規(gui)定(ding)(ding)(ding)進行養護(hu),分(fen)別測(ce)定(ding)(ding)(ding)其3d和28d的(de)(de)(de)抗壓強(qiang)(qiang)度(du)和抗折強(qiang)(qiang)度(du)。根(gen)據(ju)測(ce)定(ding)(ding)(ding)結果,按(an)(an)表2A311022-1所列的(de)(de)(de)有(you)關國家標準中的(de)(de)(de)規(gui)定(ding)(ding)(ding),可確定(ding)(ding)(ding)該水泥的(de)(de)(de)強(qiang)(qiang)度(du)等級。