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
yanhanshiqi,liqinghunningtumiancengdewendujinyuqiwen,liqingtongyulengshousuo,chanshenglayingli,zaishoudaohezaifanfuzuoyongxia,layinglijinyibuzengjia,danglayinglichaoguoliqingtonglashenqiangdushi,chanshengliewen,zailiewenliangduanchu,layingligengjiajizhong,liewenzhubuxingchengliefeng,zaochengbinghai。
玻bo纖xian土tu工gong格ge柵zha置zhi於yu瀝li青qing中zhong,使shi得de瀝li青qing砼tong的de拉la伸shen強qiang度du大da大da提ti高gao,足zu夠gou抵di抗kang住zhu較jiao大da的de拉la應ying力li而er不bu致zhi發fa生sheng路lu麵mian破po壞huai,即ji使shi因yin為wei局ju部bu區qu域yu產chan生sheng微wei小xiao裂lie紋wen,裂lie紋wen處chu的de應ying力li集ji中zhong,經jing玻bo纖xian土tu工gong格ge柵zha的de傳chuan遞di而er消xiao失shi,裂lie紋wen不bu會hui發fa展zhan成cheng裂lie縫feng。
(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。 |