芒果视频下载

一、混凝土的凝結時間

根據水泥的(de)具體性質(zhi)及混(hun)凝(ning)(ning)土(tu)所摻外加劑的(de)性能不同，混(hun)凝(ning)(ning)土(tu)的(de)初(chu)凝(ning)(ning)時(shi)(shi)(shi)間(jian)(jian)(jian)及終(zhong)凝(ning)(ning)時(shi)(shi)(shi)間(jian)(jian)(jian)會有差別。為(wei)便于(yu)(yu)施工(gong)，常態混(hun)凝(ning)(ning)土(tu)的(de)初(chu)凝(ning)(ning)時(shi)(shi)(shi)間(jian)(jian)(jian)不得小(xiao)(xiao)于(yu)(yu)3～4小(xiao)(xiao)時(shi)(shi)(shi)；終(zhong)凝(ning)(ning)時(shi)(shi)(shi)間(jian)(jian)(jian)不得大于(yu)(yu)12小(xiao)(xiao)時(shi)(shi)(shi)。一般控制(zhi)在6～10小(xiao)(xiao)時(shi)(shi)(shi)。根據施工(gong)需(xu)要，選擇適合的(de)外加劑，可以在一定的(de)范(fan)圍內(nei)改變混(hun)凝(ning)(ning)土(tu)的(de)初(chu)、終(zhong)凝(ning)(ning)時(shi)(shi)(shi)間(jian)(jian)(jian)。國家(jia)標(biao)準規定水泥初(chu)凝(ning)(ning)時(shi)(shi)(shi)間(jian)(jian)(jian)不得早于(yu)(yu)45分(fen)鐘，一般為(wei)1～3小(xiao)(xiao)時(shi)(shi)(shi)；終(zhong)凝(ning)(ning)時(shi)(shi)(shi)間(jian)(jian)(jian)不得遲于(yu)(yu)12小(xiao)(xiao)時(shi)(shi)(shi)，一般為(wei)5～8小(xiao)(xiao)時(shi)(shi)(shi)。

二、混凝土一方多少噸

普通混凝土因為強度和等級的不同，在重量上也有一定的差異，常規的混凝土一般有C10、C15、C20、C25、C30、C35、C40等級，最高的能達到C80。以C10為例，一立方C10混凝土通常需要用到水泥100公斤，砂石780公斤，碎石1025公斤，水160公斤，摻合料220公斤，總重量2285公斤。通常混凝土的等級越高，重量約大，選擇的混凝土品牌以強度(du)等級(ji)高為宜。

三、混凝土配合比

混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)施(shi)(shi)工(gong)(gong)(gong)配合(he)比(bi)(bi)是指混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)中各(ge)組成材(cai)料之間的(de)(de)比(bi)(bi)例關系，混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)配合(he)比(bi)(bi)設(she)計(ji)(ji)是混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)工(gong)(gong)(gong)程中很重要的(de)(de)一項工(gong)(gong)(gong)作，它直(zhi)接(jie)影響到混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)的(de)(de)順(shun)利施(shi)(shi)工(gong)(gong)(gong)、混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)工(gong)(gong)(gong)程的(de)(de)質量(liang)和混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)工(gong)(gong)(gong)程的(de)(de)成本。設(she)計(ji)(ji)混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)配合(he)比(bi)(bi)的(de)(de)基本要求(qiu)(qiu)是滿足混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)設(she)計(ji)(ji)的(de)(de)強度等級(ji)、施(shi)(shi)工(gong)(gong)(gong)要求(qiu)(qiu)的(de)(de)混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)和易(yi)性(xing)、混(hun)(hun)(hun)(hun)(hun)凝(ning)(ning)土(tu)(tu)使用要求(qiu)(qiu)的(de)(de)耐久(jiu)性(xing)，在滿足以上要求(qiu)(qiu)的(de)(de)基礎上降低成本。

四、混凝土強度低怎么辦

混(hun)凝(ning)(ning)(ning)土(tu)強(qiang)(qiang)(qiang)(qiang)度(du)低(di)(di)可(ke)(ke)通過提高(gao)(gao)水(shui)(shui)泥(ni)強(qiang)(qiang)(qiang)(qiang)度(du)等級來(lai)增大混(hun)凝(ning)(ning)(ning)土(tu)強(qiang)(qiang)(qiang)(qiang)度(du)；施工時，一般通過降低(di)(di)水(shui)(shui)灰比來(lai)提高(gao)(gao)混(hun)凝(ning)(ning)(ning)土(tu)強(qiang)(qiang)(qiang)(qiang)度(du)。適當(dang)降低(di)(di)水(shui)(shui)灰比，可(ke)(ke)有效控(kong)制漿(jiang)集比和水(shui)(shui)泥(ni)漿(jiang)層(ceng)厚度(du)，使集料(liao)的(de)(de)骨架作用得到充分發揮，最終能(neng)增強(qiang)(qiang)(qiang)(qiang)混(hun)凝(ning)(ning)(ning)土(tu)強(qiang)(qiang)(qiang)(qiang)度(du)。此外，還可(ke)(ke)以(yi)通過優化設計工藝(yi)流程、選擇(ze)級配優良(liang)、砂(sha)率適中的(de)(de)高(gao)(gao)強(qiang)(qiang)(qiang)(qiang)度(du)碎石、采(cai)用濕熱處理養護混(hun)凝(ning)(ning)(ning)土(tu)、適量添加外加劑和摻合料(liao)等方(fang)法來(lai)增加強(qiang)(qiang)(qiang)(qiang)度(du)。