基于活性氧化鎂的碳化砌體生產(chǎn)技術(shù)研發(fā)
發(fā)布時間：2019-03-01 21:30
【摘要】：目前,我國砌體主要有燒結(jié)粘土磚、蒸壓硅酸鹽磚和混凝土空心砌塊,由于粘土磚的生產(chǎn)破壞了大量的耕地資源,我國在十幾年前就提出了“禁粘”。蒸壓硅酸鹽磚和混凝土空心砌塊相對來說對耕地資源破壞較小,但是其中的主要原料——硅酸鹽水泥(波特蘭水泥)存在嚴(yán)重的環(huán)境問題:(1)資源和能源消耗嚴(yán)重。我國水泥工業(yè)每生產(chǎn)1噸水泥熟料平均需要消耗0.11噸標(biāo)準(zhǔn)煤、0.13噸粘土和0.95噸石灰石,且是一個不可逆的過程,即不可持續(xù)。(2)二氧化碳排放和大氣污染嚴(yán)重。水泥生產(chǎn)過程中會釋放出大量的二氧化碳,平均每生產(chǎn)1噸水泥需向大氣排放0.95噸的二氧化碳,水泥工業(yè)排放的二氧化碳占世界人為排放二氧化碳的10%左右,除了二氧化碳之外,在水泥的生產(chǎn)過程中,還有大量的粉塵、煙塵以及二氧化硫、氮氧化物、氟氣等有毒氣體排入大氣中,對環(huán)境造成很大的污染。另外,水泥制品需要一定的養(yǎng)護時間,一般需要一個月以上才能達到設(shè)計強度、承受荷載。針對上述技術(shù)問題,本研究使用活性氧化鎂來替代傳統(tǒng)硅酸鹽水泥,用于砌塊的固化劑,通過碳化技術(shù),使得活性氧化鎂反應(yīng)生成堿式碳酸鎂,來增加砌塊的抗壓強度及耐久性能,同時對試塊進行微觀測試,并分析其碳化機理。主要的試驗過程和成果如下:(1)通過室內(nèi)試驗,在實驗室通過小型攪拌機將骨料、活性氧化鎂和水?dāng)嚢杈鶆?然后通過制樣機制作小尺寸砌體試樣。試樣經(jīng)過短期養(yǎng)護后,移到小型碳化養(yǎng)護箱中對試樣進行碳化,然后進行抗壓強度測試和碳化程度測試(即二氧化碳的吸收率,通過化學(xué)中和法確定)。通過設(shè)計多種試驗方法,比較測試效果,得出活性氧化鎂碳化砌塊的最佳配比為:砂37%,碎石53%,粉煤灰3%,普通水泥3.5%,活性氧化鎂3.5%;最佳碳化環(huán)境為:濕度60%,溫度20℃,20%CO_2;最佳成型方式:10MPa壓力成型;最佳水灰比為1.0。(2)在(1)的基礎(chǔ)上,選取最優(yōu)碳化砌體,按照國家相關(guān)標(biāo)準(zhǔn)規(guī)范進行干濕循環(huán)、凍融循環(huán)等耐久性測試,并與常規(guī)水泥砌體進行對比�；钚匝趸V碳化砌塊在碳化3d達到甚至超過80%抗壓強度,碳化14d就能夠達到其最大抗壓強度,相對于普通水泥砌塊養(yǎng)護28d節(jié)約了一半的時間,且活性氧化鎂碳化砌塊的抗壓強度是普通水泥砌塊的2-3倍,且其耐久性優(yōu)于常規(guī)水泥砌體。(3)在(1)、(2)的基礎(chǔ)上,選取典型的碳化砌體試樣進行微觀化學(xué)測試,初步計劃進行的試驗包括X射線衍射(XRD)、掃描電鏡(SEM)、熱重分析(TGA)等,分析試樣的碳化反應(yīng)機理,以及碳化產(chǎn)物與環(huán)境的相互作用機理。結(jié)果表明:活性氧化鎂碳化反應(yīng)生成了三水合碳酸鎂和堿式碳酸鎂,有效填充了砌塊內(nèi)部的孔隙,且碳化產(chǎn)物為網(wǎng)狀的微觀結(jié)構(gòu),具有非常強的膠結(jié)能力,這些是活性氧化鎂碳化砌塊強度高的原因。(4)在室內(nèi)試驗的基礎(chǔ)上,采用最優(yōu)的碳化砌體原材料,在工廠研發(fā)相應(yīng)的生產(chǎn)設(shè)備和工藝,進行商業(yè)碳化砌體的試制,并按照國家相關(guān)標(biāo)準(zhǔn)檢測砌體質(zhì)量,綜合評價其經(jīng)濟和環(huán)境效應(yīng),為推廣應(yīng)用奠定基礎(chǔ)。結(jié)果表明:相對于普通水泥砌塊,活性氧化鎂作為砌體固化劑可以減少約48.1%能耗和50.53%CO_2排放,且具有較大的社會經(jīng)濟效益。
[Abstract]:At present, there are mainly sintered clay brick, autoclaved silicate brick and concrete hollow block in our country. Because the production of clay brick has destroyed a lot of cultivated land resources, our country put forward the "forbidden stick" more than a decade ago. Autoclaved silicate bricks and concrete hollow blocks have relatively little damage to the cultivated land resources, but the main raw materials _ Portland cement (Portland cement) have serious environmental problems: (1) resources and energy consumption are serious. The average consumption of 1 ton of cement clinker in China's cement industry needs to consume 0.11 tons of standard coal, 0.13 ton of clay and 0.95 tons of limestone, and is an irreversible process, that is, unsustainable. (2) Carbon dioxide emission and atmospheric pollution are serious. a large amount of carbon dioxide can be released during the production process of the cement, and an average of 1 ton of cement is produced to discharge 0.95 tons of carbon dioxide to the atmosphere, the carbon dioxide emitted by the cement industry accounts for about 10 percent of the carbon dioxide in the world, and in addition to the carbon dioxide, in the production process of the cement, There are also a large amount of dust, smoke, sulfur dioxide, nitrogen oxides, fluorine gas and other toxic gases into the atmosphere, causing great pollution to the environment. In addition, a certain curing time is required for the cement product, and the design strength can be met for more than one month, and the load can be borne. in the light of the technical problem, the active magnesium oxide is used for replacing the traditional silicate cement, the curing agent for the building block is used for producing basic magnesium carbonate through the reaction of the active magnesium oxide through the carbonization technology, the compressive strength and the durability of the building block can be increased, At the same time, the test block was micro-tested and its carbonization mechanism was analyzed. The main test procedures and results are as follows: (1) The aggregate, active magnesium oxide and water are uniformly stirred by a small mixer in a laboratory by a laboratory test, and then a small-sized masonry sample is produced by a prototype. After short-term curing, the sample is moved to a small-scale carbonization curing box for carbonization, and then the compression strength test and the degree of carbonization are tested (i.e., the absorption rate of carbon dioxide is determined by the chemical neutralization method). By designing a variety of test methods and comparing the test results, the optimum proportion of the active magnesium oxide carbonized block is as follows:37% of sand,53% of broken stone,3% of fly ash, 3.5% of common cement and 3.5% of active magnesium oxide; the optimum carbonization environment is: humidity 60%, temperature 20 鈩，
本文編號：2432820
[Abstract]:At present, there are mainly sintered clay brick, autoclaved silicate brick and concrete hollow block in our country. Because the production of clay brick has destroyed a lot of cultivated land resources, our country put forward the "forbidden stick" more than a decade ago. Autoclaved silicate bricks and concrete hollow blocks have relatively little damage to the cultivated land resources, but the main raw materials _ Portland cement (Portland cement) have serious environmental problems: (1) resources and energy consumption are serious. The average consumption of 1 ton of cement clinker in China's cement industry needs to consume 0.11 tons of standard coal, 0.13 ton of clay and 0.95 tons of limestone, and is an irreversible process, that is, unsustainable. (2) Carbon dioxide emission and atmospheric pollution are serious. a large amount of carbon dioxide can be released during the production process of the cement, and an average of 1 ton of cement is produced to discharge 0.95 tons of carbon dioxide to the atmosphere, the carbon dioxide emitted by the cement industry accounts for about 10 percent of the carbon dioxide in the world, and in addition to the carbon dioxide, in the production process of the cement, There are also a large amount of dust, smoke, sulfur dioxide, nitrogen oxides, fluorine gas and other toxic gases into the atmosphere, causing great pollution to the environment. In addition, a certain curing time is required for the cement product, and the design strength can be met for more than one month, and the load can be borne. in the light of the technical problem, the active magnesium oxide is used for replacing the traditional silicate cement, the curing agent for the building block is used for producing basic magnesium carbonate through the reaction of the active magnesium oxide through the carbonization technology, the compressive strength and the durability of the building block can be increased, At the same time, the test block was micro-tested and its carbonization mechanism was analyzed. The main test procedures and results are as follows: (1) The aggregate, active magnesium oxide and water are uniformly stirred by a small mixer in a laboratory by a laboratory test, and then a small-sized masonry sample is produced by a prototype. After short-term curing, the sample is moved to a small-scale carbonization curing box for carbonization, and then the compression strength test and the degree of carbonization are tested (i.e., the absorption rate of carbon dioxide is determined by the chemical neutralization method). By designing a variety of test methods and comparing the test results, the optimum proportion of the active magnesium oxide carbonized block is as follows:37% of sand,53% of broken stone,3% of fly ash, 3.5% of common cement and 3.5% of active magnesium oxide; the optimum carbonization environment is: humidity 60%, temperature 20 鈩，
本文編號：2432820
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