反(fan)射(she)裂(lie)縫(feng)是(shi)瀝(li)青(qing)路(lu)麵(mian)普(pu)遍(bian)存(cun)在(zai)的(de)一(yi)種(zhong)病(bing)害(hai)現(xian)象(xiang)。根(gen)據(ju)國(guo)內(nei)外(wai)道(dao)路(lu)工(gong)程(cheng)的(de)實(shi)踐(jian),在(zai)瀝(li)青(qing)麵(mian)層(ceng)和(he)中(zhong)集(ji)瀝(li)青(qing)混(hun)合(he)料(liao)層(ceng)或(huo)粗(cu)集(ji)瀝(li)青(qing)混(hun)合(he)料(liao)層(ceng)之(zhi)間(jian)鋪(pu)設(she)一(yi)層(ceng)土(tu)工(gong)織(zhi)物(wu),可(ke)用(yong)以(yi)消(xiao)除(chu)或(huo)減(jian)緩(huan)麵(mian)層(ceng)反(fan)射(she)裂(lie)縫(feng)的(de)產(chan)生(sheng),從(cong)而(er)延(yan)長(chang)道(dao)路(lu)的(de)使(shi)用(yong)壽(shou)命(ming),降(jiang)低(di)維(wei)修(xiu)成(cheng)本(ben)。但(dan)是(shi),由(you)於(yu)瀝(li)青(qing)路(lu)麵(mian)澆(jiao)注(zhu)時(shi)的(de)溫(wen)度(du)高(gao)達(da)160℃-180℃,致使土工織物褶皺、變形、ruanhua,shiqixingnengdadajiangdi,budannanyixiaochuhuojianhuanmiancengfansheliefengdechansheng,erqieshideliqinglumiangengjiaaotubuping,erboxiantugonggezhasuoteyoudexingneng,wanquanmanzuliqinglumiandeyaoqiu,muqianxuduogongchengyishiyongboxiantugonggezha。
玻纖應用於瀝青道路時,可在以下幾方麵發揮作用。
(1)抗疲勞開裂
瀝(li)青(qing)路(lu)麵(mian)必(bi)須(xu)具(ju)有(you)一(yi)定(ding)的(de)承(cheng)載(zai)能(neng)力(li),在(zai)規(gui)定(ding)的(de)時(shi)間(jian)內(nei)不(bu)能(neng)發(fa)生(sheng)疲(pi)勞(lao)破(po)壞(huai)。瀝(li)青(qing)路(lu)麵(mian)在(zai)直(zhi)接(jie)與(yu)車(che)輪(lun)接(jie)觸(chu)的(de)下(xia)麵(mian)層(ceng)受(shou)到(dao)壓(ya)力(li),在(zai)輪(lun)載(zai)邊(bian)緣(yuan)以(yi)外(wai)的(de)區(qu)域(yu),麵(mian)層(ceng)受(shou)到(dao)拉(la)力(li)作(zuo)用(yong),由(you)於(yu)兩(liang)處(chu)受(shou)力(li)區(qu)域(yu)所(suo)受(shou)力(li)性(xing)質(zhi)不(bu)同(tong),而(er)又(you)彼(bi)此(ci)緊(jin)靠(kao),因(yin)此(ci)在(zai)兩(liang)塊(kuai)受(shou)力(li)區(qu)域(yu)的(de)交(jiao)界(jie)處(chu)即(ji)力(li)的(de)突(tu)變(bian)處(chu)發(fa)生(sheng)破(po)壞(huai),在(zai)長(chang)期(qi)荷(he)載(zai)的(de)作(zuo)用(yong)下(xia),發(fa)生(sheng)疲(pi)勞(lao)開(kai)裂(lie)。
玻bo纖xian土tu工gong格ge柵zha在zai瀝li青qing麵mian層ceng中zhong,能neng夠gou將jiang上shang述shu的de壓ya應ying力li與yu拉la應ying力li分fen散san,在zai兩liang塊kuai受shou力li區qu域yu之zhi間jian形xing成cheng緩huan衝chong帶dai,減jian少shao了le應ying力li突tu變bian對dui瀝li青qing麵mian層ceng的de破po壞huai。同tong時shi玻bo璃li纖xian維wei土tu工gong格ge柵zha的de低di延yan伸shen率lv減jian少shao了le路lu麵mian的de彎wan沉chen量liang,保bao證zheng了le路lu麵mian不bu會hui發fa生sheng過guo度du變bian形xing。
(2) 耐高溫車轍
瀝(li)青(qing)混(hun)凝(ning)土(tu)在(zai)高(gao)溫(wen)時(shi)具(ju)有(you)流(liu)變(bian)性(xing),在(zai)車(che)輛(liang)荷(he)載(zai)作(zuo)用(yong)下(xia),受(shou)力(li)區(qu)域(yu)產(chan)生(sheng)凹(ao)陷(xian),車(che)輛(liang)荷(he)載(zai)撤(che)除(chu)後(hou),瀝(li)青(qing)麵(mian)層(ceng)無(wu)法(fa)完(wan)全(quan)恢(hui)複(fu)原(yuan)狀(zhuang)態(tai),即(ji)產(chan)生(sheng)了(le)塑(su)性(xing)變(bian)形(xing),在(zai)車(che)輛(liang)反(fan)複(fu)碾(nian)壓(ya)的(de)作(zuo)用(yong)下(xia),塑(su)性(xing)變(bian)形(xing)不(bu)斷(duan)積(ji)累(lei),形(xing)成(cheng)車(che)轍(zhe)。通(tong)過(guo)瀝(li)青(qing)麵(mian)層(ceng)結(jie)構(gou)分(fen)析(xi)可(ke)知(zhi),高(gao)溫(wen)下(xia)的(de)瀝(li)青(qing)混(hun)凝(ning)土(tu)在(zai)受(shou)到(dao)荷(he)載(zai)的(de)碾(nian)壓(ya)作(zuo)用(yong),形(xing)成(cheng)了(le)微(wei)量(liang)的(de)波(bo)形(xing)流(liu)變(bian),麵(mian)層(ceng)中(zhong)沒(mei)有(you)任(ren)何(he)可(ke)以(yi)約(yue)束(shu)瀝(li)青(qing)混(hun)凝(ning)土(tu)流(liu)變(bian)的(de)骨(gu)架(jia)材(cai)料(liao),造(zao)成(cheng)瀝(li)青(qing)麵(mian)層(ceng)流(liu)變(bian)的(de)累(lei)積(ji)疊(die)加(jia),這(zhe)是(shi)形(xing)成(cheng)車(che)轍(zhe)的(de)根(gen)本(ben)所(suo)在(zai)。
在zai瀝li青qing麵mian層ceng中zhong使shi用yong玻bo纖xian土tu工gong格ge柵zha,其qi在zai瀝li青qing麵mian層ceng中zhong起qi到dao骨gu架jia作zuo用yong,瀝li青qing砼tong中zhong集ji料liao貫guan穿chuan於yu格ge柵zha間jian,形xing成cheng複fu合he力li學xue嵌qian鎖suo體ti係xi,限xian製zhi集ji料liao運yun動dong,增zeng加jia了le瀝li青qing麵mian層ceng中zhong的de橫heng向xiang約yue束shu力li,瀝li青qing麵mian層ceng中zhong各ge部bu分fen彼bi此ci牽qian製zhi,防fang止zhi了le瀝li青qing麵mian層ceng的de推tui移yi,從cong而er起qi到dao抵di抗kang車che轍zhe的de作zuo用yong。
(3) 抗低溫縮裂
嚴(yan)寒(han)時(shi)期(qi),瀝(li)青(qing)混(hun)凝(ning)土(tu)麵(mian)層(ceng)的(de)溫(wen)度(du)近(jin)於(yu)氣(qi)溫(wen),瀝(li)青(qing)砼(tong)遇(yu)冷(leng)收(shou)縮(suo),產(chan)生(sheng)拉(la)應(ying)力(li),在(zai)受(shou)到(dao)荷(he)載(zai)反(fan)複(fu)作(zuo)用(yong)下(xia),拉(la)應(ying)力(li)進(jin)一(yi)步(bu)增(zeng)加(jia),當(dang)拉(la)應(ying)力(li)超(chao)過(guo)瀝(li)青(qing)砼(tong)拉(la)伸(shen)強(qiang)度(du)時(shi),產(chan)生(sheng)裂(lie)紋(wen),在(zai)裂(lie)紋(wen)兩(liang)端(duan)處(chu),拉(la)應(ying)力(li)更(geng)加(jia)集(ji)中(zhong),裂(lie)紋(wen)逐(zhu)步(bu)形(xing)成(cheng)裂(lie)縫(feng),造(zao)成(cheng)病(bing)害(hai)。
boxiantugonggezhazhiyuliqingzhong,shideliqingtongdelashenqiangdudadatigao,zugoudikangzhujiaodadelayinglierbuzhifashenglumianpohuai,jishiyinweijubuquyuchanshengweixiaoliewen,liewenchudeyinglijizhong,jingboxiantugonggezhadechuandierxiaoshi,liewenbuhuifazhanchengliefeng。
(4) 延緩反射裂縫
裂lie縫feng產chan生sheng的de反fan射she有you兩liang種zhong,一yi種zhong是shi麵mian層ceng產chan生sheng裂lie縫feng後hou,裂lie縫feng向xiang下xia反fan射she,破po壞huai下xia層ceng結jie構gou,降jiang低di路lu麵mian結jie構gou強qiang度du,在zai雨yu水shui時shi節jie,水shui進jin入ru裂lie縫feng中zhong,在zai交jiao通tong荷he載zai(輪胎壓力)的(de)反(fan)複(fu)抵(di)壓(ya),水(shui)在(zai)裂(lie)縫(feng)中(zhong)產(chan)生(sheng)水(shui)壓(ya),水(shui)不(bu)斷(duan)的(de)衝(chong)擊(ji)瀝(li)青(qing)混(hun)合(he)料(liao),導(dao)致(zhi)裂(lie)縫(feng)擴(kuo)大(da)。另(ling)一(yi)種(zhong)是(shi)舊(jiu)麵(mian)層(ceng)原(yuan)有(you)裂(lie)縫(feng),路(lu)基(ji)層(ceng)或(huo)下(xia)層(ceng)路(lu)基(ji)層(ceng)產(chan)生(sheng)的(de)裂(lie)縫(feng)向(xiang)上(shang)反(fan)射(she),新(xin)罩(zhao)路(lu)麵(mian)無(wu)法(fa)承(cheng)受(shou)因(yin)底(di)層(ceng)移(yi)動(dong)而(er)產(chan)生(sheng)的(de)剪(jian)切(qie)力(li)和(he)抗(kang)伸(shen)應(ying)力(li),導(dao)致(zhi)路(lu)麵(mian)麵(mian)層(ceng)裂(lie)縫(feng)。
在瀝青罩麵層中加鋪玻纖土工格柵夾層,抑製應力,釋放應變,增強瀝青混凝土整體強度,達到防止裂縫向上或向下反射的目的。
|