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da160℃-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)。
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(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
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。
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