普通巖棉板外保溫工程質量問題(ti)原因(yin)分析

普通巖棉裸(luo)板自身(shen)缺陷

普通巖(yan)(yan)棉裸板(ban)與(yu)其(qi)他保溫板(ban)相(xiang)比(bi)，性(xing)能相(xiang)差(cha)比(bi)較大，其(qi)強(qiang)(qiang)(qiang)度低、易(yi)剝離(li)(li)分層、吸水(shui)率高、憎水(shui)性(xing)差(cha)、易(yi)吸濕(shi)膨脹，用于(yu)外保溫工(gong)(gong)程(cheng)中存在著一(yi)定的缺(que)陷，易(yi)引起質量問題。目前市場上巖(yan)(yan)棉板(ban)主要(yao)是采用擺錘法工(gong)(gong)藝(yi)(yi)生產的，該工(gong)(gong)藝(yi)(yi)可(ke)(ke)使巖(yan)(yan)棉纖(xian)維部分呈豎(shu)向(xiang)分布，可(ke)(ke)提(ti)高巖(yan)(yan)棉板(ban)的壓縮強(qiang)(qiang)(qiang)度和層間結合強(qiang)(qiang)(qiang)度，壓縮強(qiang)(qiang)(qiang)度可(ke)(ke)達(da)到40kPa，抗剝離(li)(li)強(qiang)(qiang)(qiang)度也可(ke)(ke)達(da)到14kPa，垂(chui)直板(ban)面的抗拉強(qiang)(qiang)(qiang)度可(ke)(ke)超過(guo)7.5kPa，但要(yao)用于(yu)外保溫工(gong)(gong)程(cheng)時，這(zhe)種強(qiang)(qiang)(qiang)度還遠遠不夠。

(1)抗(kang)拉強度低(di)，普(pu)通巖棉(mian)保溫板的抗(kang)拉強度不足(zu)0.01MPa

(2)普通巖棉裸板在自然環境特別是濕熱條件下尺寸很不穩定。巖棉板主要由橫向分布的纖維絲構成，纖維遇水后吸水分層，變形嚴重，巖棉吸水重量大，強度低，上墻后沉降導致空鼓，脫落，劣質巖棉板更為明顯。河南巖棉板

(3)普通(tong)巖棉裸板(ban)纖維(wei)與纖維(wei)之(zhi)間存在著連通(tong)空氣，在熱脹冷縮(suo)和負風壓作用(yong)下(xia)極易蓬松、鼓脹。

(4)普通巖(yan)棉裸(luo)板應用(yong)于外墻工程中時，其面層(ceng)難(nan)以抵御膨(peng)脹的應力變形，上墻后勢必造成外飾面效果不佳，并出現鼓包、板縫明(ming)顯等現象。

風壓破壞

由(you)于普通(tong)巖棉(mian)裸(luo)(luo)板(ban)構造疏散，垂直板(ban)面方(fang)向的(de)抗(kang)拉強度低，同時其(qi)密度比(bi)較大(da)(da)，因此無(wu)法直接采用膠粘(zhan)劑將其(qi)粘(zhan)貼固定在基層(ceng)墻體上，必須用一(yi)定數(shu)量(liang)的(de)錨栓來固定巖棉(mian)板(ban)。若普通(tong)巖棉(mian)裸(luo)(luo)板(ban)與基層(ceng)墻體的(de)結合力不夠(gou)大(da)(da)，無(wu)法滿足*負風壓作(zuo)用時，必然會(hui)被(bei)刮落。同時，由(you)于普通(tong)巖棉(mian)裸(luo)(luo)板(ban)強度比(bi)較低，也易被(bei)大(da)(da)風撕裂。

若錨(mao)(mao)(mao)栓(shuan)(shuan)直(zhi)接錨(mao)(mao)(mao)固在普(pu)通巖棉(mian)(mian)裸板(ban)上，在巨(ju)大(da)的(de)負風壓力作用下，錨(mao)(mao)(mao)栓(shuan)(shuan)僅(jin)能保護住錨(mao)(mao)(mao)栓(shuan)(shuan)盤所覆蓋(gai)的(de)部(bu)位，普(pu)通巖棉(mian)(mian)裸板(ban)會直(zhi)接被拔(ba)掉如下圖所示，錨(mao)(mao)(mao)固巖棉(mian)(mian)板(ban)的(de)錨(mao)(mao)(mao)栓(shuan)(shuan)已失去(qu)作用。河南巖棉(mian)(mian)板(ban)

若錨栓(shuan)(shuan)(shuan)質量不過關，則錨栓(shuan)(shuan)(shuan)也會被破(po)壞，錨栓(shuan)(shuan)(shuan)桿(gan)會被拉彎(wan)如下圖所(suo)示，錨栓(shuan)(shuan)(shuan)與基層墻體結合力不夠時，錨栓(shuan)(shuan)(shuan)也被直(zhi)接拔出，錨固巖(yan)棉板的錨栓(shuan)(shuan)(shuan)遭到破(po)壞。河(he)南(nan)巖(yan)棉板

采用鋼(gang)(gang)網配合錨栓(shuan)來(lai)固定普(pu)通巖棉裸板(ban)時，若錨栓(shuan)數量不夠，也無法滿足抵(di)抗(kang)風壓(ya)的(de)作用，同樣會造成巖棉板(ban)連帶(dai)鋼(gang)(gang)網一起(qi)脫落(luo)事故如下圖(tu)所示。在混凝土剪力墻(qiang)中鋼(gang)(gang)筋較多，鉆(zhan)頭(tou)在墻(qiang)面鉆(zhan)孔時極易碰到(dao)螺紋鋼(gang)(gang)受到(dao)損壞，錨釘的(de)錨固深度和錨固數量難以保證(zheng)。

構造設計不合理

出現面(mian)(mian)(mian)層(ceng)(ceng)開(kai)(kai)裂的(de)普(pu)通(tong)(tong)巖(yan)(yan)(yan)棉(mian)(mian)(mian)裸(luo)(luo)板(ban)(ban)(ban)(ban)外保溫(wen)工(gong)程(cheng)通(tong)(tong)常采(cai)用的(de)是(shi)直(zhi)接(jie)在普(pu)通(tong)(tong)巖(yan)(yan)(yan)棉(mian)(mian)(mian)裸(luo)(luo)板(ban)(ban)(ban)(ban)外表面(mian)(mian)(mian)做(zuo)薄抹(mo)(mo)面(mian)(mian)(mian)層(ceng)(ceng)，即抹(mo)(mo)聚(ju)合(he)物水泥(ni)砂(sha)漿復合(he)耐堿玻纖(xian)網來(lai)增強抗裂防護效(xiao)果。但是(shi)，由(you)于普(pu)通(tong)(tong)巖(yan)(yan)(yan)棉(mian)(mian)(mian)裸(luo)(luo)板(ban)(ban)(ban)(ban)強度低、易(yi)(yi)吸(xi)水、易(yi)(yi)分(fen)(fen)層(ceng)(ceng)，板(ban)(ban)(ban)(ban)材柔軟(ruan)且具有彈(dan)性(xing)，與(yu)聚(ju)合(he)物水泥(ni)砂(sha)漿相(xiang)(xiang)比，二者的(de)彈(dan)性(xing)模量、線(xian)膨(peng)(peng)脹系數等物理(li)指標以及熱工(gong)性(xing)能相(xiang)(xiang)差很大，因此(ci)，若(ruo)直(zhi)接(jie)采(cai)用水泥(ni)砂(sha)漿或聚(ju)合(he)物水泥(ni)砂(sha)漿等密度比較大、偏剛性(xing)的(de)材料(liao)對普(pu)通(tong)(tong)巖(yan)(yan)(yan)棉(mian)(mian)(mian)裸(luo)(luo)板(ban)(ban)(ban)(ban)抹(mo)(mo)面(mian)(mian)(mian)處(chu)理(li)，則(ze)易(yi)(yi)使面(mian)(mian)(mian)層(ceng)(ceng)發生(sheng)開(kai)(kai)裂、起(qi)鼓、脫落(luo)等不良現象。同時，由(you)于普(pu)通(tong)(tong)巖(yan)(yan)(yan)棉(mian)(mian)(mian)裸(luo)(luo)板(ban)(ban)(ban)(ban)面(mian)(mian)(mian)層(ceng)(ceng)纖(xian)維易(yi)(yi)斷裂脫落(luo)，與(yu)抹(mo)(mo)面(mian)(mian)(mian)層(ceng)(ceng)材料(liao)的(de)結合(he)度很差，也會(hui)引起(qi)抹(mo)(mo)面(mian)(mian)(mian)層(ceng)(ceng)開(kai)(kai)裂甚(shen)至脫落(luo)現象。另外，巖(yan)(yan)(yan)棉(mian)(mian)(mian)吸(xi)濕膨(peng)(peng)脹或受熱膨(peng)(peng)脹也會(hui)致抹(mo)(mo)面(mian)(mian)(mian)層(ceng)(ceng)遭到破(po)壞。普(pu)通(tong)(tong)巖(yan)(yan)(yan)棉(mian)(mian)(mian)裸(luo)(luo)板(ban)(ban)(ban)(ban)的(de)易(yi)(yi)吸(xi)水性(xing)還會(hui)導(dao)致抹(mo)(mo)面(mian)(mian)(mian)砂(sha)漿中的(de)水分(fen)(fen)易(yi)(yi)被巖(yan)(yan)(yan)棉(mian)(mian)(mian)板(ban)(ban)(ban)(ban)奪走(zou)，造成抹(mo)(mo)面(mian)(mian)(mian)層(ceng)(ceng)快速失水而(er)得(de)不到有效(xiao)養(yang)護而(er)開(kai)(kai)裂。