土工膜初是(shi)從(cong)石(shi)油瀝(li)青(qing)得到的(de)(de)高分子聚合(he)(he)物,這種材(cai)(cai)料(liao)(liao)(liao)(liao)包攬了(le)(le)當時(shi)科技的(de)(de)精(jing)髓。隨著(zhu)石(shi)油工(gong)(gong)業的(de)(de)發展(zhan)(zhan),許多(duo)從(cong)石(shi)油中(zhong)(zhong)提取出來(lai)的(de)(de)新(xin)材(cai)(cai)料(liao)(liao)(liao)(liao)也(ye)都(dou)有了(le)(le)新(xin)的(de)(de)用途(tu),給予了(le)(le)石(shi)油更多(duo)的(de)(de)用途(tu),在整個過程中(zhong)(zhong),土(tu)(tu)工(gong)(gong)膜(mo)(mo)各項指標逐漸發展(zhan)(zhan),為土(tu)(tu)工(gong)(gong)膜(mo)(mo)的(de)(de)發展(zhan)(zhan)打下(xia)堅實(shi)的(de)(de)基礎。新(xin)型土(tu)(tu)工(gong)(gong)膜(mo)(mo)使(shi)用壽命提升(sheng),抗拉能力(li)也(ye)有所提升(sheng),這些(xie)都(dou)為實(shi)際工(gong)(gong)程提供了(le)(le)便利。一九(jiu)三(san)零~一九(jiu)四零年(nian)之間,人(ren)類在游泳池(chi)防(fang)滲中(zhong)(zhong)先使(shi)用了(le)(le)聚氯(lv)乙(yi)烯(xi)(xi)膜(mo)(mo),這個階段基本上(shang)是(shi)人(ren)們廣泛應用土(tu)(tu)工(gong)(gong)合(he)(he)成(cheng)(cheng)材(cai)(cai)料(liao)(liao)(liao)(liao)的(de)(de)開(kai)始(shi);一九(jiu)五三(san)年(nian),在渠(qu)道(dao)防(fang)滲中(zhong)(zhong)人(ren)們又借(jie)鑒了(le)(le)日(ri)本游泳池(chi)防(fang)滲的(de)(de)成(cheng)(cheng)功經驗,再次使(shi)用了(le)(le)聚氯(lv)乙(yi)烯(xi)(xi)膜(mo)(mo)對(dui)進行防(fang)滲處(chu)理;19世紀50年(nian)代后,渠(qu)道(dao)、水庫和土(tu)(tu)石(shi)壩等工(gong)(gong)程使(shi)用塑料(liao)(liao)(liao)(liao)薄(bo)膜(mo)(mo)材(cai)(cai)料(liao)(liao)(liao)(liao)進行防(fang)滲已成(cheng)(cheng)為一種普(pu)遍(bian)現(xian)象。一般情況(kuang)下(xia),土(tu)(tu)工(gong)(gong)膜(mo)(mo)大致有兩類:瀝(li)青(qing)土(tu)(tu)工(gong)(gong)膜(mo)(mo)和聚合(he)(he)物土(tu)(tu)工(gong)(gong)膜(mo)(mo)。為保證土(tu)(tu)工(gong)(gong)膜(mo)(mo)在工(gong)(gong)程應用中(zhong)(zhong)不會造成(cheng)(cheng)工(gong)(gong)程事(shi)故(gu),通常(chang)對(dui)其進行加(jia)筋和不加(jia)筋或組合(he)(he)處(chu)理。制造土(tu)(tu)工(gong)(gong)膜(mo)(mo)的(de)(de)原(yuan)材(cai)(cai)料(liao)(liao)(liao)(liao)較多(duo),可分為以下(xia)幾類

(1)化學混(hun)類(lei):將二(er)種(zhong)或(huo)二(er)種(zhong)以上(shang)的(de)高分子混(hun)合,如氯磺化聚乙(yi)烯( CSPE )。

(2)生產(chan)瀝青和環氧樹(shu)脂(zhi),如改性瀝青和聚砜樹(shu)脂(zhi)等。

復(fu)合(he)(he)土(tu)(tu)工(gong)膜(mo)(mo)(mo),是把傳統(tong)土(tu)(tu)工(gong)膜(mo)(mo)(mo)與土(tu)(tu)工(gong)布(bu)結(jie)合(he)(he)在一塊的(de)(de)(de)新產品。復(fu)合(he)(he)土(tu)(tu)工(gong)膜(mo)(mo)(mo)的(de)(de)(de)制造方法通常是將(jiang)單層布(bu)和單層膜(mo)(mo)(mo)一起壓制形(xing)成(cheng),或(huo)者是將(jiang)單層布(bu)與單層膜(mo)(mo)(mo)復(fu)合(he)(he)形(xing)成(cheng)二層。形(xing)式為(wei)一布(bu)一膜(mo)(mo)(mo),同(tong)理(li),若將(jiang)兩層布(bu)與單層膜(mo)(mo)(mo)復(fu)合(he)(he)形(xing)成(cheng)三層,則該形(xing)式為(wei)兩布(bu)一膜(mo)(mo)(mo)。復(fu)合(he)(he)土(tu)(tu)工(gong)膜(mo)(mo)(mo)的(de)(de)(de)防滲性(xing)、適應(ying)變形(xing)能(neng)(neng)力以及耐老化能(neng)(neng)力優良,因此,在實際工(gong)程應(ying)用中對復(fu)合(he)(he)土(tu)(tu)工(gong)膜(mo)(mo)(mo)的(de)(de)(de)防滲能(neng)(neng)力、耐久性(xing)能(neng)(neng)和抗(kang)老化能(neng)(neng)力更(geng)為(wei)看重。復(fu)合(he)(he)土(tu)(tu)工(gong)膜(mo)(mo)(mo)是將(jiang)傳統(tong)土(tu)(tu)工(gong)膜(mo)(mo)(mo)材料(liao)與土(tu)(tu)工(gong)織物結(jie)合(he)(he)而制成(cheng)的(de)(de)(de),其工(gong)程特點比較于傳統(tong)單一材料(liao)有著如下優勢:

(1)復合土(tu)工(gong)膜(mo)抗拉和抗刺破等能力較單(dan)層土(tu)工(gong)膜(mo)要強許多。

(2)在(zai)同等(deng)應力條件下,復合(he)土工膜的(de)延伸長(chang)度要(yao)小于單一材料。

(3)復合土工膜更加趨(qu)向各項同性,能(neng)防止當(dang)物(wu)理環境變(bian)化和氣溫改變(bian)時(shi)會產生(sheng)朝一個方面的(de)變(bian)化。

(4)復合土(tu)工膜能夠(gou)提(ti)高(gao)土(tu)工膜和土(tu)體之間的(de)摩阻力,從而(er)提(ti)高(gao)了(le)其穩定性。

由(you)于(yu)復合(he)(he)(he)土(tu)工(gong)(gong)膜(mo)是由(you)土(tu)工(gong)(gong)膜(mo)和土(tu)工(gong)(gong)布二類材質所綜合(he)(he)(he)組成的(de),其力學性(xing)質既有(you)膜(mo)又有(you)布的(de)特點,因此(ci),復合(he)(he)(he)土(tu)工(gong)(gong)膜(mo)的(de)抗拉強度(du)和抗刺破(po)能力等相比(bi)于(yu)單(dan)層(ceng)土(tu)工(gong)(gong)膜(mo)有(you)明顯的(de)提升。當(dang)復合(he)(he)(he)土(tu)工(gong)(gong)膜(mo)在(zai)接受拉應(ying)力后(hou),或土(tu)工(gong)(gong)布完(wan)全破(po)裂時,復合(he)(he)(he)土(tu)工(gong)(gong)膜(mo)和土(tu)工(gong)(gong)布都具有(you)一致(zhi)的(de)應(ying)力﹣應(ying)變(bian)曲線(xian);土(tu)工(gong)(gong)布破(po)壞后(hou),由(you)于(yu)砼(tong)(tong)層(ceng)有(you)良好的(de)擴(kuo)展(zhan)性(xing),此(ci)時的(de)土(tu)工(gong)(gong)薄膜(mo)和砼(tong)(tong)層(ceng)具有(you)一致(zhi)的(de)應(ying)力﹣應(ying)變(bian)曲線(xian)。復合(he)(he)(he)土(tu)工(gong)(gong)薄膜(mo)屋(wu)頂漏水性(xing)的(de)高低主(zhu)要(yao)取決于(yu)砼(tong)(tong)層(ceng)的(de)延展(zhan)性(xing),而不受砼(tong)(tong)層(ceng)的(de)強度(du)限制。