分類:技術知識發布時間:2016/08/26
斜屋面作為(wei)一種新型的(de)建筑設(she)計形式,在(zai)施(shi)工(gong)技(ji)(ji)術上比平屋面有(you)一定的(de)技(ji)(ji)術難點(dian),在(zai)施(shi)工(gong)過(guo)程中(zhong),針對(dui)這(zhe)些技(ji)(ji)術難點(dian),嚴格按施(shi)工(gong)規范的(de)要求,做好施(shi)工(gong)技(ji)(ji)術方案,并在(zai)施(shi)工(gong)中(zhong)認真加以實施(shi),就能高(gao)質量地完成斜屋面工(gong)程的(de)施(shi)工(gong)。
一、施工方法
①單面模板法
此(ci)法(fa)是(shi)坡(po)屋面(mian)混凝(ning)(ning)土(tu)施工中(zhong)較(jiao)常用的(de)(de)簡(jian)易法(fa),但影(ying)響澆筑質(zhi)量的(de)(de)方面(mian)較(jiao)多(duo),如(ru)屋面(mian)坡(po)度(du)(du)的(de)(de)大小(xiao)、模板(ban)的(de)(de)光滑(hua)程度(du)(du)和坍落度(du)(du)的(de)(de)影(ying)響等(deng)。因混凝(ning)(ning)土(tu)無法(fa)按(an)常規振搗(dao)而導(dao)致(zhi)不密實,須待(dai)混凝(ning)(ning)土(tu)處(chu)于初(chu)凝(ning)(ning)階段(duan)再(zai)(zai)振搗(dao)。此(ci)時混凝(ning)(ning)土(tu)的(de)(de)可塑性降低(di),再(zai)(zai)振搗(dao)勢必造成(cheng)混凝(ning)(ning)土(tu)的(de)(de)內傷(shang)和裂紋。為此(ci),在(zai)施工中(zhong)應采用一些(xie)措施,如(ru)控制混凝(ning)(ning)土(tu)坍落度(du)(du)在(zai)30~50mm,利用焊接板(ban)筋(jin)做抗(kang)滑(hua)移(yi)帶和確定(ding)混凝(ning)(ning)土(tu)流向、分(fen)段(duan)施工等(deng)。為了保證板(ban)面(mian)的(de)(de)平整(zheng)度(du)(du),隨搗(dao)隨用1∶2.5水泥砂漿抹平。
②雙面夾板法
屋面(mian)坡度要達到75°,必(bi)須(xu)采(cai)用雙面(mian)夾板法才(cai)能保證施(shi)(shi)工(gong)質量(liang)。施(shi)(shi)工(gong)需要用短鋼(gang)筋(jin)作支(zhi)架,并加(jia)設(she)止(zhi)水片(pian),以(yi)控(kong)制屋面(mian)厚度和止(zhi)水、防滲。在兩(liang)模(mo)板外側面(mian)中(zhong)部設(she)尺(chi)寸為400mm×400mm混凝土澆筑孔。
二、方法選擇
1、單面模板法
斜屋面(mian)(mian)(mian)混凝(ning)(ning)土(tu)(tu)在(zai)單面(mian)(mian)(mian)模板(ban)上施(shi)工主要靠混凝(ning)(ning)土(tu)(tu)自身的凝(ning)(ning)結力、模板(ban)面(mian)(mian)(mian)的摩阻(zu)力和鋼筋網的張(zhang)拉阻(zu)力的限制,至混凝(ning)(ning)土(tu)(tu)硬(ying)化成(cheng)型后(hou)不(bu)再沿斜面(mian)(mian)(mian)下(xia)滑。如果模板(ban)超過一定角度(du)后(hou),在(zai)混凝(ning)(ning)土(tu)(tu)振搗時,模板(ban)對混凝(ning)(ning)土(tu)(tu)的摩阻(zu)力不(bu)足(zu)以抵消混凝(ning)(ning)土(tu)(tu)順(shun)模板(ban)面(mian)(mian)(mian)的下(xia)滑力。混凝(ning)(ning)土(tu)(tu)初凝(ning)(ning)前,如緩慢位移持續發(fa)生,易導致混凝(ning)(ning)土(tu)(tu)不(bu)密實和內傷(shang)而滲(shen)漏。故建議當屋面(mian)(mian)(mian)的坡(po)度(du)大于26°時,不(bu)宜采(cai)用單面(mian)(mian)(mian)模板(ban)法(fa)施(shi)工。
2、雙面夾板法
雙面(mian)模板(ban)(ban)(ban)法(fa)可以(yi)保(bao)(bao)證混(hun)凝土(tu)板(ban)(ban)(ban)達到(dao)內實(shi)外光的要求。但由于(yu)板(ban)(ban)(ban)的厚度小(xiao)(一(yi)般僅為100mm),除去(qu)鋼(gang)筋和(he)保(bao)(bao)護層(ceng),中間(jian)間(jian)隙小(xiao)于(yu)50mm,若鋼(gang)筋綁扎存在誤差,則振(zhen)搗棒更難(nan)插(cha)入(ru)。因(yin)此(ci)施(shi)工(gong)中必須(xu)注意防止鋼(gang)筋位(wei)移(yi)及因(yin)混(hun)凝土(tu)澆筑不到(dao)位(wei)而造(zao)成的蜂窩(wo)。因(yin)無法(fa)觀(guan)察到(dao)模板(ban)(ban)(ban)內混(hun)凝土(tu)的飽滿度,可敲擊進(jin)行聽音(yin)檢查,并在板(ban)(ban)(ban)底采(cai)用附著(zhu)式振(zhen)搗器,使混(hun)凝土(tu)下淌充實(shi)。振(zhen)搗時(shi),采(cai)用直徑33mm的小(xiao)振(zhen)動(dong)棒,按序插(cha)振(zhen),防止漏插(cha)。對于(yu)死角部(bu)位(wei)可以(yi)采(cai)用板(ban)(ban)(ban)外振(zhen)與人工(gong)插(cha)釬(han)相結合。對于(yu)此(ci)法(fa)施(shi)工(gong),應嚴格控制混(hun)凝土(tu)的坍(tan)落度,具(ju)體根(gen)據(ju)施(shi)工(gong)時(shi)的溫度確定,一(yi)般控制在50~70mm。為保(bao)(bao)證層(ceng)面(mian)的結構安全和(he)防水(shui)效(xiao)果(guo),對坡度大的斜屋(wu)面(mian),應優(you)先選(xuan)用雙面(mian)夾板(ban)(ban)(ban)法(fa)。
三(san)、斜屋面混凝土工程的施(shi)工
根據(ju)現(xian)行(xing)的(de)(de)設(she)計規(gui)范,現(xian)澆屋(wu)面板(ban)面的(de)(de)混(hun)(hun)凝土(tu)要(yao)具(ju)有一(yi)定(ding)的(de)(de)抗滲(shen)要(yao)求,一(yi)般(ban)選(xuan)用(yong)抗滲(shen)混(hun)(hun)凝土(tu),為(wei)確保混(hun)(hun)凝土(tu)拌(ban)制(zhi)質量,對骨(gu)料(liao)(liao)的(de)(de)要(yao)求應更為(wei)嚴格(ge),砂(sha)子應為(wei)中砂(sha)且含泥量不得(de)超過5%,碎石粒徑以5~30mm為(wei)宜且含泥量不得(de)大于2%,骨(gu)料(liao)(liao)級配要(yao)合理,以增(zeng)加混(hun)(hun)凝土(tu)的(de)(de)和易性。根據(ju)施(shi)工經驗(yan),要(yao)嚴格(ge)控制(zhi)混(hun)(hun)凝土(tu)的(de)(de)水灰比,混(hun)(hun)凝土(tu)的(de)(de)坍落度(du)以10~15cm左右為(wei)宜。
斜(xie)屋(wu)面(mian)尤(you)其是(shi)陡斜(xie)屋(wu)面(mian)的混(hun)凝(ning)(ning)土(tu)澆(jiao)筑,大(da)的問(wen)題是(shi)混(hun)凝(ning)(ning)土(tu)滑動流淌造成局(ju)部(bu)離(li)析(xi)而(er)發生混(hun)凝(ning)(ning)土(tu)的質量問(wen)題,澆(jiao)筑時(shi)(shi)混(hun)凝(ning)(ning)土(tu)傾(qing)落高度不大(da)于600mm,因(yin)此(ci)不能(neng)從跳板(ban)上直(zhi)接從高處(chu)向下傾(qing)倒(dao)混(hun)凝(ning)(ning)土(tu),混(hun)凝(ning)(ning)土(tu)澆(jiao)筑時(shi)(shi)增加板(ban)面(mian)作(zuo)業工人,特別在屋(wu)面(mian)低(di)處(chu)澆(jiao)筑混(hun)凝(ning)(ning)土(tu)時(shi)(shi),建議全部(bu)用小桶(tong)水平(ping)運輸混(hun)凝(ning)(ning)土(tu)(禁止用斗車),一(yi)小桶(tong)一(yi)小桶(tong)平(ping)鋪,這樣可避免作(zuo)業工人施工中貪圖(tu)容易,盲目傾(qing)倒(dao)混(hun)凝(ning)(ning)土(tu),造成混(hun)凝(ning)(ning)土(tu)離(li)析(xi)。
混(hun)(hun)凝(ning)土澆(jiao)筑(zhu)(zhu)時應(ying)從屋面兩頭低處同時開(kai)始(shi),兩面坡(po)面同時澆(jiao)注為佳,混(hun)(hun)凝(ning)土的澆(jiao)筑(zhu)(zhu)應(ying)連續(xu)施工(gong)不留置(zhi)(zhi)施工(gong)縫(feng)。如特(te)殊情(qing)況必須留置(zhi)(zhi)施工(gong)縫(feng)時,施工(gong)縫(feng)的位置(zhi)(zhi)應(ying)在(zai)結(jie)構(gou)受力(li)較小處,一般距(ju)現(xian)(xian)澆(jiao)板(ban)(ban)支座1m,不可在(zai)現(xian)(xian)澆(jiao)板(ban)(ban)中心部(bu)位置(zhi)(zhi)留置(zhi)(zhi)施工(gong)縫(feng)。
斜(xie)屋面(mian)(mian)(mian)(mian)的(de)混(hun)(hun)凝土(tu)(tu)(tu)振(zhen)(zhen)搗密(mi)實一(yi)(yi)(yi)直是一(yi)(yi)(yi)個施(shi)工(gong)難(nan)題,為控制板(ban)的(de)澆(jiao)筑(zhu)厚(hou)度(du),應在板(ban)面(mian)(mian)(mian)(mian)按(an)1000mm×1000mm均勻(yun)布置厚(hou)度(du)控制點。根據經(jing)驗(yan)認為,對(dui)(dui)于(yu)梁的(de)振(zhen)(zhen)搗要特別注意插式振(zhen)(zhen)動(dong)(dong)器振(zhen)(zhen)搗在各區段均勻(yun),振(zhen)(zhen)搗時(shi)間過(guo)長易(yi)造(zao)成局部粗骨(gu)料集中(zhong),砂漿(jiang)與粗骨(gu)料分離。對(dui)(dui)于(yu)板(ban)面(mian)(mian)(mian)(mian)混(hun)(hun)凝土(tu)(tu)(tu),振(zhen)(zhen)搗過(guo)多(duo)混(hun)(hun)凝土(tu)(tu)(tu)易(yi)流動(dong)(dong),造(zao)成板(ban)面(mian)(mian)(mian)(mian)平整(zheng)度(du)難(nan)以控制,一(yi)(yi)(yi)般做法是在施(shi)工(gong)中(zhong)先用人工(gong)均勻(yun)攤鋪混(hun)(hun)凝土(tu)(tu)(tu),注意混(hun)(hun)凝土(tu)(tu)(tu)厚(hou)度(du)應足(zu)(zu)夠,用抹子拍實,待混(hun)(hun)凝土(tu)(tu)(tu)接近初(chu)凝時(shi)用平板(ban)振(zhen)(zhen)動(dong)(dong)器按(an)板(ban)塊的(de)澆(jiao)筑(zhu)順(shun)序(xu)均勻(yun)走二遍,接槎處則應多(duo)走一(yi)(yi)(yi)遍即可,板(ban)面(mian)(mian)(mian)(mian)振(zhen)(zhen)搗后(hou)再用人工(gong)對(dui)(dui)局部不平整(zheng)及板(ban)厚(hou)度(du)不足(zu)(zu)的(de)板(ban)面(mian)(mian)(mian)(mian)進(jin)行修(xiu)整(zheng),然后(hou)用水泥(ni)砂漿(jiang)對(dui)(dui)板(ban)面(mian)(mian)(mian)(mian)混(hun)(hun)凝土(tu)(tu)(tu)表面(mian)(mian)(mian)(mian)修(xiu)整(zheng),以取得良好的(de)表面(mian)(mian)(mian)(mian)觀感(gan)。
混(hun)凝土澆(jiao)(jiao)筑完成后要做好澆(jiao)(jiao)水(shui)養護(hu),由于(yu)夏(xia)季氣溫高(gao),水(shui)份蒸(zheng)發量大,斜屋(wu)面澆(jiao)(jiao)水(shui)養護(hu)效果差,因此夏(xia)季施工(gong)后應強調使用草(cao)袋覆蓋養護(hu)為佳,以防止混(hun)凝土因暴曬而碳化和縮(suo)水(shui)龜裂,澆(jiao)(jiao)水(shui)濕潤養護(hu)不得少于(yu)14d。