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。
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。 |