
鋼結構廠房具有強度高、重量輕、抗震性能好、工業化程度高、施工速度快等優點。但鋼材耐腐蝕性差、對鋼結構廠房的耐久性有著不利影響。因此,鋼結構廠房的防腐、好壞直接影響到建筑物的安全和使用,本文淺析在鋼結構廠房防腐蝕中的一些體會。
鋼結構廠房防腐蝕設計
(1)鋼(gang)結(jie)構廠(chang)房(fang)防(fang)(fang)(fang)(fang)腐(fu)應遵循預防(fang)(fang)(fang)(fang)為主(zhu)、防(fang)(fang)(fang)(fang)護(hu)結(jie)合(he)(he)的(de)(de)原則。設(she)計(ji)時應對廠(chang)房(fang)所處的(de)(de)環(huan)境(jing)(jing)、狀況、鋼(gang)材(cai)種類、基(ji)層處理(li)、涂層結(jie)構、厚度(du)、施工(gong)(gong)方法、造價以及使(shi)用(yong)年限等(deng)(deng)因(yin)素(su)綜(zong)合(he)(he)考慮。工(gong)(gong)業(ye)鋼(gang)結(jie)構構件腐(fu)蝕,按其(qi)介(jie)(jie)(jie)質(zhi)的(de)(de)存(cun)在形(xing)態分(fen)為:氣態介(jie)(jie)(jie)質(zhi)、液(ye)態介(jie)(jie)(jie)質(zhi)和(he)固(gu)態介(jie)(jie)(jie)質(zhi)。各種介(jie)(jie)(jie)質(zhi)按其(qi)性質(zhi)、含(han)量和(he)環(huan)境(jing)(jing)條(tiao)(tiao)件劃(hua)分(fen)類別。根(gen)據(ju)(ju)類別又分(fen)為強腐(fu)蝕、中腐(fu)蝕、弱腐(fu)蝕和(he)微(wei)腐(fu)蝕四(si)個(ge)防(fang)(fang)(fang)(fang)護(hu)等(deng)(deng)級(ji)(ji)。一般工(gong)(gong)業(ye)建筑(zhu)的(de)(de)鋼(gang)結(jie)構廠(chang)房(fang)主(zhu)要(yao)以氣態介(jie)(jie)(jie)質(zhi)的(de)(de)酸、堿、鹽類腐(fu)蝕為主(zhu),尤其(qi)是(shi)化工(gong)(gong)、有色(se)冶金(jin)行業(ye)的(de)(de)鋼(gang)結(jie)構廠(chang)房(fang)。依據(ju)(ju)車(che)間生產環(huan)境(jing)(jing)狀況,腐(fu)蝕介(jie)(jie)(jie)質(zhi)和(he)強度(du)等(deng)(deng)級(ji)(ji),合(he)(he)理(li)劃(hua)分(fen)防(fang)(fang)(fang)(fang)腐(fu)分(fen)區。確(que)定(ding)防(fang)(fang)(fang)(fang)腐(fu)蝕材(cai)料(liao)的(de)(de)合(he)(he)理(li)選擇,主(zhu)要(yao)承重構件、次要(yao)構件以及維(wei)護(hu)結(jie)構應區別對待(dai),防(fang)(fang)(fang)(fang)腐(fu)材(cai)料(liao)分(fen)別選擇。依據(ju)(ju)防(fang)(fang)(fang)(fang)腐(fu)蝕等(deng)(deng)級(ji)(ji)工(gong)(gong)作環(huan)境(jing)(jing)和(he)維(wei)護(hu)條(tiao)(tiao)件綜(zong)合(he)(he)確(que)定(ding)廠(chang)房(fang)建筑(zhu)物防(fang)(fang)(fang)(fang)腐(fu)蝕的(de)(de)設(she)計(ji)使(shi)用(yong)年限。
(2)結構性防腐:主要是鋼結構廠房構件的型式、鋼材的銹蝕等級和構件截面選擇和截面厚度要求,以及鋼構件安裝時對螺栓(直徑大于12mm)、螺母、墊圈和焊縫的要求,均應滿足《工業建筑防腐蝕設計標準》的要求。重要構件優先選用耐候鋼材。裸露的鋼柱柱腳應采用混凝土包裹。
(3)廠房建筑防(fang)腐(fu)(fu)(fu):主要(yao)有(you)鋼(gang)(gang)材基(ji)(ji)層(ceng)(ceng)(ceng)(ceng)表面(mian)處(chu)理(li),即(ji)除(chu)(chu)銹方法和等級的(de)(de)(de)(de)確定、涂(tu)(tu)(tu)(tu)(tu)(tu)料(liao)(liao)品種(zhong)(zhong)、涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)結(jie)(jie)構以及(ji)厚度(du)選(xuan)擇。目前鋼(gang)(gang)結(jie)(jie)構防(fang)腐(fu)(fu)(fu)涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)做法有(you)三類(lei):第一(yi)(yi)類(lei)是(shi)(shi)在(zai)噴鍍金層(ceng)(ceng)(ceng)(ceng)表面(mian)加腐(fu)(fu)(fu)蝕(shi)涂(tu)(tu)(tu)(tu)(tu)(tu)料(liao)(liao)的(de)(de)(de)(de)復合(he)(he)面(mian)層(ceng)(ceng)(ceng)(ceng);第二(er)類(lei)是(shi)(shi)含(han)有(you)富鋅(xin)底(di)漆(qi)(qi)的(de)(de)(de)(de)防(fang)腐(fu)(fu)(fu)蝕(shi)涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng);第三類(lei)是(shi)(shi)既(ji)不含(han)金層(ceng)(ceng)(ceng)(ceng)也不含(han)富鋅(xin)底(di)漆(qi)(qi)的(de)(de)(de)(de)防(fang)腐(fu)(fu)(fu)蝕(shi)涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)。工業鋼(gang)(gang)結(jie)(jie)構廠房尤其(qi)是(shi)(shi)化(hua)工、有(you)色冶金行業,目前普(pu)遍(bian)采用(yong)(yong)(yong)第二(er)類(lei),在(zai)廠房鋼(gang)(gang)結(jie)(jie)構表面(mian)涂(tu)(tu)(tu)(tu)(tu)(tu)覆富鋅(xin)底(di)漆(qi)(qi)的(de)(de)(de)(de)涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)做法,具體施工有(you)三種(zhong)(zhong)結(jie)(jie)構形式:①底(di)層(ceng)(ceng)(ceng)(ceng)—中(zhong)間(jian)層(ceng)(ceng)(ceng)(ceng)—面(mian)層(ceng)(ceng)(ceng)(ceng);②底(di)層(ceng)(ceng)(ceng)(ceng)—面(mian)層(ceng)(ceng)(ceng)(ceng);③底(di)層(ceng)(ceng)(ceng)(ceng)面(mian)層(ceng)(ceng)(ceng)(ceng)為同(tong)種(zhong)(zhong)涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)。。基(ji)(ji)層(ceng)(ceng)(ceng)(ceng)處(chu)理(li):一(yi)(yi)般防(fang)腐(fu)(fu)(fu)蝕(shi)廠房鋼(gang)(gang)構件(jian)均采用(yong)(yong)(yong)拋丸除(chu)(chu)銹,除(chu)(chu)銹等級Sa2 ,即(ji)清除(chu)(chu)鋼(gang)(gang)構件(jian)基(ji)(ji)層(ceng)(ceng)(ceng)(ceng)表面(mian)毛刺、鐵銹、油(you)污及(ji)附著物和鋼(gang)(gang)材表面(mian)的(de)(de)(de)(de)氧化(hua)皮,使構件(jian)表面(mian)露出(chu)金屬(shu)光澤。基(ji)(ji)層(ceng)(ceng)(ceng)(ceng)處(chu)理(li)越(yue)(yue)徹底(di),底(di)層(ceng)(ceng)(ceng)(ceng)涂(tu)(tu)(tu)(tu)(tu)(tu)料(liao)(liao)附著力越(yue)(yue)強,效果越(yue)(yue)好(hao),同(tong)時(shi)(shi)富鋅(xin)底(di)層(ceng)(ceng)(ceng)(ceng)涂(tu)(tu)(tu)(tu)(tu)(tu)料(liao)(liao)在(zai)電化(hua)學(xue)腐(fu)(fu)(fu)蝕(shi)中(zhong),鋅(xin)粉對鋼(gang)(gang)構件(jian)起陰極保護作(zuo)用(yong)(yong)(yong)。面(mian)層(ceng)(ceng)(ceng)(ceng)涂(tu)(tu)(tu)(tu)(tu)(tu)料(liao)(liao)的(de)(de)(de)(de)作(zuo)用(yong)(yong)(yong)是(shi)(shi)防(fang)腐(fu)(fu)(fu)、耐磨、抗老化(hua)還有(you)美觀作(zuo)用(yong)(yong)(yong)。中(zhong)間(jian)涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)主要(yao)是(shi)(shi)增加涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)厚底(di),滿足防(fang)腐(fu)(fu)(fu)蝕(shi)要(yao)求。涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)與涂(tu)(tu)(tu)(tu)(tu)(tu)層(ceng)(ceng)(ceng)(ceng)之間(jian)要(yao)作(zuo)用(yong)(yong)(yong)、性(xing)能(neng)、硬度(du)匹配相容,不能(neng)出(chu)現互熔或咬底(di)現象,結(jie)(jie)合(he)(he)良好(hao)配套使用(yong)(yong)(yong)。防(fang)腐(fu)(fu)(fu)蝕(shi)涂(tu)(tu)(tu)(tu)(tu)(tu)料(liao)(liao)品種(zhong)(zhong)繁多(duo),性(xing)能(neng)、用(yong)(yong)(yong)途、適(shi)應范圍(wei)各不相同(tong),防(fang)腐(fu)(fu)(fu)設計時(shi)(shi),一(yi)(yi)定要(yao)掌(zhang)握各類(lei)涂(tu)(tu)(tu)(tu)(tu)(tu)料(liao)(liao)的(de)(de)(de)(de)性(xing)能(neng)和使用(yong)(yong)(yong)條件(jian),了解它的(de)(de)(de)(de)優缺點,合(he)(he)理(li)選(xuan)用(yong)(yong)(yong)。