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、軟ruan化hua,使shi其qi性xing能neng大da大da降jiang低di,不bu但dan難nan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,而er且qie使shi得de瀝li青qing路lu麵mian更geng加jia凹ao凸tu不bu平ping,而er玻bo纖xian土tu工gong格ge柵zha所suo特te有you的de性xing能neng,完wan全quan滿man足zu瀝li青qing路lu麵mian的de要yao求qiu,目mu前qian許xu多duo工gong程cheng已yi使shi用yong玻bo纖xian土tu工gong格ge柵zha。
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。
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(4) 延緩反射裂縫
liefengchanshengdefansheyouliangzhong,yizhongshimiancengchanshengliefenghou,liefengxiangxiafanshe,pohuaixiacengjiegou,jiangdilumianjiegouqiangdu,zaiyushuishijie,shuijinruliefengzhong,zaijiaotonghezai(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。
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