建筑防水工程中防水材料的選擇
建(jian)(jian)筑(zhu)屋(wu)面(mian)(mian)工程防(fang)(fang)水(shui)(shui)設(she)計(ji)時,不(bu)僅要考慮建(jian)(jian)筑(zhu)物的(de)(de)性質、重要程度和使用功(gong)能(neng)要求確定防(fang)(fang)水(shui)(shui)等級(ji)和屋(wu)面(mian)(mian)做法,同時還要按照(zhao)不(bu)同地區的(de)(de)自然條件、防(fang)(fang)水(shui)(shui)材料(liao)情況、經濟技術水(shui)(shui)平(ping)和其(qi)他(ta)特殊要求等,綜合考慮其(qi)屋(wu)面(mian)(mian)的(de)(de)防(fang)(fang)水(shui)(shui)設(she)防(fang)(fang)等級(ji)、屋(wu)面(mian)(mian)形式(shi)、防(fang)(fang)水(shui)(shui)構造、防(fang)(fang)水(shui)(shui)材料(liao)的(de)(de)選用,這就是(shi)屋(wu)面(mian)(mian)防(fang)(fang)水(shui)(shui)設(she)計(ji)的(de)(de)綜合治理原則。
剛性防(fang)水材(cai)(cai)料(liao)是(shi)指以水泥、砂石為(wei)原材(cai)(cai)料(liao),或其內摻人(ren)少(shao)量外加劑、高分子聚合物等材(cai)(cai)料(liao),通過(guo)調整配(pei)合比,抑制或減少(shao)孔隙(xi)率(lv),改(gai)變孔隙(xi)特征,增加各原材(cai)(cai)料(liao)界面間的(de)密實(shi)性等方法,配(pei)制成具有一定抗滲透(tou)能力的(de)水泥砂漿混凝土類防(fang)水材(cai)(cai)料(liao)。
建筑防水工程中防水材料的選擇
應根據建(jian)筑物結構(gou)類型、防水構(gou)造形(xing)式(shi)以及節點部位外界氣候情況(kuang)(包括(kuo)溫度(du)、濕度(du)、酸雨、紫外線等)、建(jian)筑物的(de)(de)結構(gou)形(xing)式(shi)(整澆(jiao)或(huo)裝配式(shi))與跨度(du)、屋面(mian)坡度(du)、地基變形(xing)程度(du)和(he)防水層(ceng)暴露情況(kuang)等決定相適應的(de)(de)材(cai)料。
在(zai)選擇(ze)防(fang)水(shui)材料時(shi),還應考慮到施工條件(jian)和市(shi)場價(jia)格因(yin)素(su)。
例如改(gai)性(xing)(xing)瀝青防水卷材可(ke)分為彈性(xing)(xing)體、塑性(xing)(xing)體等(deng),不僅用(yong)料不同(tong),而且(qie)性(xing)(xing)能差(cha)異也很大;同(tong)時(shi)還要考(kao)慮到(dao)(dao)所選(xuan)用(yong)的材料在當(dang)地(di)的實(shi)際(ji)使(shi)用(yong)效果如何;還應考(kao)慮到(dao)(dao)與合成高(gao)分子防水卷材相(xiang)配套的粘(zhan)結劑、施(shi)工(gong)工(gong)藝等(deng)施(shi)工(gong)條件因(yin)素(su)。
施工(gong)縫(feng)采(cai)用(yong)遇水(shui)膨(peng)(peng)脹(zhang)(zhang)止水(shui)條時,止水(shui)條與施工(gong)縫(feng)基面應(ying)密(mi)貼,中間不得有(you)空鼓、脫離等現象;止水(shui)條應(ying)牢固的(de)安(an)裝在接(jie)縫(feng)表面或預留槽內,止水(shui)條采(cai)用(yong)搭(da)(da)接(jie)時,搭(da)(da)接(jie)長度不小(xiao)于(yu) 60mm;選(xuan)用(yong)的(de)遇水(shui)膨(peng)(peng)脹(zhang)(zhang)止水(shui)條應(ying)具有(you)緩脹(zhang)(zhang)性能,7d 的(de)凈膨(peng)(peng)脹(zhang)(zhang)率(lv)(lv)不宜(yi)大(da)于(yu)終(zhong)(zhong)膨(peng)(peng)脹(zhang)(zhang)率(lv)(lv)的(de) 60%,終(zhong)(zhong)膨(peng)(peng)脹(zhang)(zhang)率(lv)(lv)宜(yi)大(da)于(yu) 220%。
地(di)下(xia)(xia)防(fang)(fang)(fang)水(shui)(shui)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)包(bao)括工(gong)(gong)業與民用地(di)下(xia)(xia)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)、防(fang)(fang)(fang)護工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)、隧道(dao)及地(di)下(xia)(xia)鐵道(dao)等建筑物的(de)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)實體。地(di)下(xia)(xia)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)長期受地(di)下(xia)(xia)水(shui)(shui)或(huo)處于地(di)下(xia)(xia)水(shui)(shui)的(de)包(bao)圍之中,防(fang)(fang)(fang)水(shui)(shui)措施沒做好容(rong)易出(chu)現滲漏影響地(di)下(xia)(xia)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)實體的(de)使用,在地(di)下(xia)(xia)防(fang)(fang)(fang)水(shui)(shui)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)建設(she)中需(xu)遵(zun)循防(fang)(fang)(fang)、排、截、堵相結(jie)合,因(yin)地(di)制(zhi)宜(yi),綜合治(zhi)理。根據《地(di)下(xia)(xia)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)防(fang)(fang)(fang)水(shui)(shui)技術規范》(GB50108-2008)規定(ding)將地(di)下(xia)(xia)工(gong)(gong)程(cheng)(cheng)(cheng)(cheng)的(de)防(fang)(fang)(fang)水(shui)(shui)等級劃(hua)分為(wei)4個等級。