土工膜可分为单膜和复合土工膜有哪些特点？

土工膜可(ke)分为单(dan)膜和(he)复合土工膜。单(dan)个土工膜可(ke)以分为单(dan)层(ceng)(ceng)薄(bo)膜和(he)多层(ceng)(ceng)不(bu)(bu)同(tong)树脂构成的膜。单(dan)质膜有很(hen)好(hao)的延展(zhan)性，但(dan)耐拉性能(neng)低(di)，易断裂(lie)，且在接触(chu)尖锐物体时(shi)易被(bei)刺(ci)伤。另(ling)外，表(biao)面(mian)不(bu)(bu)粗糙，摩擦(ca)系数小，易引起膜两侧(ce)几(ji)何滑移。单(dan)层(ceng)(ceng)土工膜有许多缺点，可(ke)以加入其(qi)(qi)他材料(liao)以弥(mi)补(bu)其(qi)(qi)不(bu)(bu)足，形成一(yi)种新型(xing)材料(liao)，即复合土工膜。

复(fu)式土(tu)(tu)工膜(mo)(mo)(mo)是将土(tu)(tu)工膜(mo)(mo)(mo)的一(yi)面(mian)或两面(mian)用土(tu)(tu)工布粘结于土(tu)(tu)工膜(mo)(mo)(mo)，经一(yi)定工艺制成(cheng)土(tu)(tu)工膜(mo)(mo)(mo)组合物(wu)。按其形(xing)态可分为一(yi)布一(yi)膜(mo)(mo)(mo)和二布一(yi)膜(mo)(mo)(mo)。采用聚(ju)乙烯或聚(ju)氯乙烯对复(fu)合土(tu)(tu)工膜(mo)(mo)(mo)进行(xing)增韧(ren)改性，经压延(yan)机进行(xing)一(yi)系列加工，再与土(tu)(tu)工布经热熔粘成(cheng)型(xing)。其综(zong)合了土(tu)(tu)工织物(wu)和单膜(mo)(mo)(mo)的优点，在(zai)抗拉、抗顶(ding)破(po)、防(fang)渗透性、变形(xing)模量、延(yan)展性等(deng)物(wu)理指(zhi)标较高，而(er)且(qie)重量轻、制造成(cheng)本低(di)。

与其他防渗材料相比，该复合(he)土工(gong)(gong)(gong)膜在工(gong)(gong)(gong)程中的(de)应(ying)用(yong)(yong)越来越广，其应(ying)用(yong)(yong)范围也越来越广。根据表面(mian)形态的(de)不同，土工(gong)(gong)(gong)膜可以分(fen)为(wei)光(guang)面(mian)土工(gong)(gong)(gong)膜和糙土工(gong)(gong)(gong)膜。薄(bo)膜两面(mian)外观(guan)平整、无(wu)凸起始点且(qie)摩擦(ca)(ca)系数小(xiao)的(de)土工(gong)(gong)(gong)膜称(cheng)为(wei)光(guang)面(mian)土工(gong)(gong)(gong)膜，两边或一(yi)(yi)侧表面(mian)都有一(yi)(yi)排凸起起始点，采用(yong)(yong)一(yi)(yi)定工(gong)(gong)(gong)艺(yi)加工(gong)(gong)(gong)制成(cheng)的(de)摩擦(ca)(ca)系数较小(xiao)的(de)土工(gong)(gong)(gong)膜称(cheng)为(wei)光(guang)面(mian)土工(gong)(gong)(gong)膜。