1、外文翻譯對普通硅酸鹽水泥和粉煤灰的物理性能和力學(xué)性能的研究摘要 對高摻量粉煤灰硅酸鹽水泥做了一個實驗，來對它的物理和力學(xué)性能進(jìn)行研究。普通硅酸鹽水泥分以0,20、30、40、50、60、70%幾個等級分別被粉煤灰取代（按重量計算）。在所有的混合物中，水膠比恒定為0.3。試塊在振動臺上被振實。預(yù)期的體積密度會隨著粉煤灰摻量的增加而減少。氣孔率和吸水率會隨著水泥被粉煤灰取代而增大。添加了粉煤灰試塊的3d、7d，28d的抗壓強(qiáng)度降低了，這一點在假設(shè)粉煤灰摻量在30%以上的實驗中更加明顯。超聲波脈沖速度測試結(jié)果表明，漿體的性能會隨著混合物中粉煤灰摻量的增加而降低。關(guān)鍵詞：粉煤灰，抗壓強(qiáng)度，超聲波脈沖檢

2、測技術(shù)，水泥1 介紹 每年印度的火力發(fā)電產(chǎn)能生產(chǎn)超過1.6億噸的粉煤灰。對于火力發(fā)電廠來說，處理粉煤灰是一個很重要的問題。通常的，現(xiàn)在大量的飛灰和底灰在土地里會被用來阻塞和填充，以最小化的成本處理。在1985年，加拿大的自然資源部首先調(diào)查發(fā)現(xiàn)：大量的粉煤灰具有許多優(yōu)異的性能，各種標(biāo)準(zhǔn)規(guī)范規(guī)定在水泥行業(yè)粉煤灰的摻量不能超多35%。在印度,水泥和混凝土行業(yè)每年消耗4000萬噸粉煤灰。另一個方面，水泥需求的不斷上升可以進(jìn)一步解決高摻量粉煤灰（超過50%）在混凝土上面的應(yīng)用。這個過程顯然可以經(jīng)濟(jì)化，以及減少溫室氣體(GHG)的排放,減少廢物處置和減少健康的危害。因此在混凝土中使用高摻量粉煤灰開始興起，

3、對普通硅酸鹽水泥(OPC)混凝土應(yīng)用程序，是一個資源節(jié)約型、耐用、成本效益的、可持續(xù)的選擇 (克勞奇,lK理論研究。2007)。這項工作的目的是研究一些物理和機(jī)械屬性，如容重、孔隙率、吸水率和超聲波脈沖速度和抗壓強(qiáng)度的粉煤灰硅酸鹽水泥。2 材料和方法2.1 材料 普通硅酸鹽水泥(OPC)28天抗壓強(qiáng)度使用54 MPa。普通硅酸鹽水泥的主要性質(zhì)見表1。粉煤灰來自西孟加拉、印度的火力發(fā)電廠。水泥和粉煤灰的化學(xué)成分見表2. 粉煤灰包含非常少碳含量，正如所指出的那樣,低價值的損失在點火(LOI)。粉煤灰的硅鋁比(SiO2/Al2O3)為2.5，二氧化硅,氧化鋁和Fe2O3的總和等于95.74%。氧化鈣

4、含量小于1%。因此,按標(biāo)準(zhǔn)ASTM C 618 08，它可以分為類F粉煤灰。按照國際標(biāo)準(zhǔn)，3182-2003，它可分為硅質(zhì)粉煤灰。粉煤灰的粒子大小分布為圖一，粉煤灰為深灰色的顏色，混合物的用水為正常的飲用水。表1:普通硅酸鹽水泥的主要性質(zhì)細(xì)度比表面(m2/kg)312凝結(jié)時間(minutes)初凝180終凝290標(biāo)準(zhǔn)稠度(%)31.5表二：普通硅酸鹽水泥和粉煤灰的化學(xué)性質(zhì)SiO2Al2O3Fe2O3CaOMgOK2ONa2OSO4LOI*OPC（%）18.624.753.0261.423.211.421.512.293.55Fly Ash（%）64.5825.895.270.590.260.0

5、410.0270.312.40粒子大小、微米圖一 ：粉煤灰的粒度分布2.2 混合設(shè)計和樣品制備 表3代表了不同混合物中不同粉煤灰比例的漿體，控制的混合物沒有摻粉煤灰標(biāo)記為F0和20 - 70%的OPC，已經(jīng)被粉煤灰取代的分別標(biāo)記為F20-F70,水膠比還是保持在0.3.準(zhǔn)備好邊長50mm的立方體試模，高頻振動臺，進(jìn)行正常壓實。每組混合物準(zhǔn)備十八個試模，進(jìn)過二十四小時的養(yǎng)護(hù)，從試模中取出試塊，保持其濕度并在室溫25進(jìn)行實驗，抗壓輕度值取六個的平均值。表3 OPC和Fly Ash混合漿體的成分成分F0F20F30F40F50F60F70OPC100807060504030FLY ASH020304

6、0506070水膠比0.32.3 實驗程序 在水中養(yǎng)護(hù)7天后，測試其容重、氣孔率、孔隙率和超聲波脈沖速度，確定容重、氣孔率和吸水率。從每個組里面的取三個試塊在110的干燥箱里進(jìn)行干燥，24小時后取出稱其干重(DW)。這個試塊被放在水里煮沸2個小時，另一個則放在相同溫度下的水中24小時，來讓水滲入到毛細(xì)孔中。然后用0.5mm的銅線把試塊懸掛在水中，測定它的懸浮重量(S1 W)和以及浸泡質(zhì)量(S2 W)，記錄數(shù)據(jù)時要細(xì)心，要除去試塊表面的水和銅線的質(zhì)量。下面的方程被用來計算樣品的氣孔率和吸水率。容重（gm/cc)=氣孔率(%)=孔隙率(%)= 結(jié)果和討論 圖二表

7、示被粉煤灰取代的樣品的不一樣的體積密度，結(jié)果發(fā)現(xiàn)，水泥（1.33gm/cc）的容重比粉煤灰（0.96gm/cc）的容重高得多。正如之前所預(yù)期的，樣品的體積密度會隨著混合物粉煤灰摻量的增多而減少。 圖二 不同粉煤灰摻量下樣品的容重 圖三和圖四分別表示樣品的氣孔率和吸水率，很明顯孔隙率和吸水率在隨著粉煤灰摻量的增加而增大。這個結(jié)果表明粉煤灰對粉煤灰的微觀結(jié)構(gòu)的研究比較缺乏。圖三 不同粉煤灰摻量下樣品的孔隙率圖四 不同粉煤灰摻量下樣品的吸水率 通過采用標(biāo)準(zhǔn)13311 (Part 1) 1992中提到的方法完成了超聲波脈沖速度測試，通過這個測試來評定樣品的質(zhì)量。這個測試結(jié)果顯示,所有UPV試樣落在“好

8、”的類別。結(jié)果證實了粉煤灰增加，而UPV質(zhì)量則下降。表4:樣品的超聲波脈沖速度試驗結(jié)果(公里/秒)粉煤灰含量(%)0203040506070UPV3.783.743.733.683.643.583.55抗壓強(qiáng)度是使用壓力試驗機(jī)來進(jìn)行試驗。我們看到實驗的結(jié)果是平均抗壓強(qiáng)度的值是在反抗粉煤灰摻量的增加。結(jié)果證明樣品的3d、7d、28d抗壓強(qiáng)度隨著粉煤灰摻量的增加而降低（圖五）。當(dāng)粉煤灰含量在60%以上是抗壓強(qiáng)度下降的趨勢是最為明顯的。從實驗結(jié)果來看最優(yōu)的是粉煤灰摻量在60%（最大）。OPC中摻粉煤灰可以用于一些低強(qiáng)度混凝土和砌體工程。這將直接降低建筑成本以及減少溫室氣體的排放。圖五：粉煤灰樣品的抗

9、壓強(qiáng)度4 結(jié)論根據(jù)目前的研究,可能得出的結(jié)論是：在普通硅酸鹽水泥中摻入粉煤灰會降低其28天的抗壓強(qiáng)度。當(dāng)粉煤灰的摻量大于30%時抗壓輕度會急劇下降。凝結(jié)反應(yīng)需要時間，有時強(qiáng)度可能會增大，所以長期的研究是必要的的。粉煤灰的添加會降低容重，這會增加土木工程師對建設(shè)輕重量建筑的興趣。其他的物理性質(zhì)，比如：孔隙率和吸水率的增加會降低摻加了粉煤灰混凝土的耐久性。UPV的實驗結(jié)果表明高含量的粉煤灰會降低抗壓強(qiáng)度。5 致謝印度新德里科學(xué)技術(shù)部的對這個實驗研究提供了經(jīng)濟(jì)支持。參考文獻(xiàn) 1.k . Jain(2011),混凝土可持續(xù)發(fā)展通過創(chuàng)新材料和技術(shù)全國巡回研討會pp 46-51。 2.ASTM C618

10、- 08 a,(2008),、美國試驗材料學(xué)會、美國。Bumjoo金,莫尼卡Prezzi(2008),。克勞奇,休伊特,白阿德(2007),程序上的煤灰(WOCA),美國肯塔基州pp1 - 14。5.規(guī)范:3812(第一部分)。(2003)、粉煤灰-規(guī)范-第1部分:粉煤灰用作火山灰水泥,水泥砂漿和混凝土印度,新德里標(biāo)準(zhǔn)。6.規(guī)范：13311(第1部分)(1992),:第1部分超聲波脈沖速度、印度新德里標(biāo)準(zhǔn)。7.馬爾霍特拉。(1986),混凝土國際、8(28),pp28-31。Study on the physical and mechanical property of ordinary po

11、rtland cement and fly ash pasteABSTRACT An experimental investigation has been carried out to study the physical and mechanical property of high volume fly ash cement paste. Ordinary portland cement was replaced by 0,20, 30, 40, 50, 60 and 70 % class F fly ash (by weight). Water- binder ratio in all

12、 mixture was kept constant at 0.3. Cube specimens were compacted in table vibrator. As expected bulk density decreases with fly ash increment in the mixture. Apparent porosity and water absorption value increases with replacement of cement by fly ash. Results confirm the decrease in compressive stre

13、ngth at 3, 7 and 28 day with fly ash addition and it is more prominent in case of more than 30% fly ash content mixes. Ultrasonic pulse velocity test results indicate that the quality of the paste deteriorate with increase of fly ash content in the mixture.Keywords: Fly Ash, OPC, Compressive Strengt

14、h, Pastes, UPV.Introduction More than 160 million tonnes of fly ash is being produced by thermal power plant in India(A. K. Jain, 2011). The disposal of fly ash is now a significant concern for the electricity manufacturing plants. Commonly, huge volume of fly ash and bottom ash are now being either

15、 ponded or used as land filling to minimize the disposal cost (Bumjoo Kim and Monica Prezzi, 2008). In the year 1985 CANMET first investigate and confirmed that high volume of fly ash has many excellent properties (V.M. Malhotra, 1986). Various standard codes limited the use of quality fly ash up to

16、 35% in cement industry. In India, cement and concrete industry consumes about 40 million tonnes of fly ash . On the other hand, the rising of cement demand can be further resolved by utilizing high volume (more than 50 %) of fly ash in the concrete. This process obviously will be economical as well

17、 as reduce greenhouse gas (GHG) emission, minimize waste disposal and health hazards. Thus the use of high volumefly ash in concrete has recently gained popularity as a resource-efficient, durable, costeffective, sustainable option for ordinary portland cement (OPC) concrete applications (Crouch, L.

18、 K et.al. 2007). The aim of this work is to study some physical and mechanical properties such as bulk density, apparent porosity, water absorption and ultrasonic pulse velocity and compressive strength of ordinary portland cement- fly ash pastes (without any aggregate).2. Materials and Method2.1 Ma

19、terials Ordinary Portland Cement (OPC) having 28 day compressive strength of 54 MPa was used. Typical properties of the OPC used are given in table 1. The fly ash was collected from National Thermal Power Plant, Farakka, West Bengal, India. Chemical composition of both cement and fly ash is shown in

20、 table 2. The fly ash contains very less carbon content as indicated by the low value of loss on ignition (LOI). Silica to alumina ratio (SiO2/Al2O3) of the fly ash was 2.5.The sum total of SiO2, Al2O3 and Fe2O3 equal to 95.74%.Calcium oxide (CaO) content was less than 1%. Hence, as per ASTM C 618-0

21、8, it can be classified as class F fly ash. Based on IS: 3812 (Part I)-2003 it can be classified as siliceous pulverized fuel ash. The particle size distribution of fly ash has been given in Figure 1. The fly ash showed a dark gray colour. Normal potable water was used in making the mixture。2.2 Mix

22、Design and Specimens Preparation Table 3 represents the mixture proportion of different fly ash-cement pastes. The control mixture without fly ash has been marked as F0 and 20 to 70% OPC have been replaced by fly ash and marked as F20 to F70 respectively. The water- binder ratio was kept constant at

23、 0.3.Specimens of 50mm cubes were prepared and properly compacted with high frequency vibrating table. Eighteen cubes were cast for each mixture. After 24 hours of casting, the cubes were removed from the mould, and were cured in water at ambient temperature of 25OC till testing. The compressive str

24、ength value for a typical mixture at a particular age is based on the average of six cubes.2.3 Test procedure Bulk density, apparent porosity, water absorption and ultrasonic pulse velocity has been measure after 7 day water curing. To determine the bulk density, apparent porosity and water absorpti

25、on of the fly ash-cement paste specimens, three cubes from each series were dried in hot air oven at 110OC for 24 hours and its weight was taken as dry weight (DW). The specimens were then boiled in water for 2 hours and kept for another 24 hours in the same warm water to penetrate water in the pore

26、s. Specimens were then suspended in water with copper wire of 0.5 mm thickness to take the suspended weight (S1 W) as well as soaked weight (S2 W) was also recorded by carefully removing the surface water and the copper wire. The following equations were used to find out the apparent porosity and wa

27、ter absorption of the specimens.Results and Discussions Figure 2 represent the bulk density of different OPC replaced fly ash paste specimens. It was found that the bulk density of the cement was much higher (1.32 gm/cc) compare to fly ash (0.96 gm/cc). As expected, the bulk density of the specimens

28、 decreases with increase of fly ash in the mixture.Figure 3 and Figure 4 represent the apparent porosity and water absorption of the specimens.Both the apparent porosity and water absorption value increased with fly ash replacement.This result indicates the poor microstructure with high amount of fl

29、y ash pastes.Ultrasonic pulse velocity test has been done to assess the quality of paste specimens by method mentioned at IS: 13311 (Part 1) 1992. It is evident from the UPV test results that all the test specimens fall in “GOOD” category. With fly ash increase the UPV results confirms the deteriora

30、tion in quality.The compressive strength was determined using a digital compression testing machine. The maximum load at failure reading was taken and the average compressive strength has been plotted against fly ash content. It is evident that the compressive strength of the specimens decreases wit

31、h increase of fly ash in the mixture at 3, 7 and 28 day (Figure 5). The drop in compressive strength is prominent when fly ash content in the mix increased above 30%. From the experimental result optimally 60% (max.) fly ash content OPC can be used for some low strength concrete and masonry works. T

32、his will directly reduce the cost of construction as well as reduce the green house gas emission.ConclusionOn the basis of the present study, it may be concluded that, in general use of fly ash inordinary portland cement decreases the compressive strength up to 28 days. Sharp drop in compressive str

33、ength is found for more than 30% fly ash content mixes. As the pozzolanic reaction usually takes time, the strength may get increased over time and some long term study is needed. Bulk density decreased with fly ash addition which may be of good interest for the civil engineer for light weight of th

34、e construction. Others physical property such as apparent porosity and water absorption begin to increase with fly ash increment which may harm the durability of high fly ash content concrete. UPV result confirms the poor quality of paste with high fly ash content.5 AcknowledgementThe financial assistance to this experimental study received from Department of Science and Technology (DST PURSE SCHEME), Govt. of India, New Delhi.6 References1. K. Jain (2011), “Fly ash utilization in Indian Cement Industry: current status andfuture prospects”, Proceeding of the Natio