外文翻譯--礦物摻合料的綜合效應(yīng)與強塑劑混合水泥漿的流動性

1、<p><b>　　中文4300字</b></p><p>　　Combined effect of mineral admixtures with superplasticizers on the fluidity of the blended cement paste</p><p><b>　　Abstract：</b></

2、p><p>　　The new concrete often incorporates several organic and mineral admixtures which interact with the various constituents of the cements and cause some problems of hardness and workability. In the present

3、 study, limestone cement (C1) and pozzolanic cement (C2) were used to make cement paste with two types of superplasticizer; SP1 based on polynaphthalene sulphonate (PNS); and SP2 based on resins melamines (PRM). Marsh co

4、ne test was adopted to check the combined effects of the following factors on </p><p>　　Keywords：Cement，Limestone powder，Natural pozzolan，Superplasticizer，F(xiàn)luidity</p><p>　　1. Introduction</p

5、><p>　　Currently, the essential novelty appeared in cement industry is actually the increase use of the mineral admixtures, substituting a part of cement to reduce the carbonic gas emission, to minimize the cem

6、ent cost and to improve some technical performances.</p><p>　　High performances concretes made with low W/C ratio require the use of suitable and compatible superplasticizers with the new cements which can t

7、ransform a concrete with high consistency into a concrete with high workability. During the use of superplasticizers in concrete, certain cements can sometimes present some problems of incompatibility of cement–superplas

8、ticizer; irregularity of slump and rapid workability loss. The principal approach provided to combat against this difficulty is to sele</p><p>　　The incorporation of some mineral admixtures such as blast fur

9、nace slag, fly ash, silica fume or natural pozzolan can make the interaction between the cementitious materials and superplasticizers more complex, and therefore the selection of the compatible couple requires further co

10、nsideration.</p><p>　　The adsorption of superplasticizer molecules on hydrated phases creates an electrostatically charged germ which participates to the electrostatic repulsion and avoids flocculation.</

11、p><p>　　Also, the cement paste characterized by the long needle of ettringite formed at early age usually decreases the paste fluidity .</p><p>　　There exists an optimum soluble alkali content with

12、 respect to the fluidity and fluidity loss, which was found to be 0.4–0.5% Na2O equivalent. At this optimum alkali content, the initial fluidity is maximum and fluidity loss is minimum.</p><p>　　Neubauer et

13、al.[4]noted that superplasticizer causes the zeta potential of the cement pastes to become increasingly negative; it suggests that this superplasticizer begins to disperse the cement particles. When new superplasticizers

14、 are developed, an interaction problem must be anticipated, cement and superplasticizer will be able to cause sharp variation in fluidity and produce stiffness, depending upon the combination of cement and superplasticiz

15、erSwamy et al. works concluded that it is possib</p><p>　　The results conducted by Duval and Kadri confirmed that the superplasticizer adsorption depends both on the amount of C3A and the presence of soluble

16、 alkali sulphates in the cement. It was proved that the incorporation of fly ash in concrete reduces the need of superplasticizer necessary to obtain a similar slump flow compared with the concrete containing only cement

17、 as binder. On the other hand, Sone et al. observed a total loss of fluidity when Portland cement was replaced by blended cement, w</p><p>　　When the superplasticizer presents a compatibility with a certain

18、mixture composition, it will lose it as soon as the mineral admixture is substituted. Similarly, Bensebti and Houarifound that the fluidity of the cement paste decreases with the introduction of the fillers, this reducti

19、on is proportional to their replacement level and type.</p><p>　　The investigation of cement–superplasticizer (C–SP) compatibility can be realized by measuring flow time of grout as proposed by several resea

20、rchers[11–13]. The cement paste fluidity results usually are represented by a curve indicating the flow time C–SP system according to superplasticizer dosage at 5 and 60 min age.</p><p>　　The type of curve o

21、btained presents three essential points which control the rheological behavior of the cement–superplasticizer studied and are expressed as follows:</p><p>　　Saturation superplasticizer dosage corresponding t

22、o a break in the curve when superplasticizer is added over the saturation point; it does not improve any more the fluidity of C–SP but only increases the risk of sedimentation and delays the cement setting time.</p>

23、;<p>　　Fluidity level reached for this saturated dosage (flow time); which will be small as much as the paste is fluid. In this text, the fluidity term is the opposite of viscosity.</p><p>　　Fluidity

24、loss related to the two curves at 5 and 60 min; it can be expressed by the difference between these two times, which must be very low for compatible couples of cement–superplasticizer.</p><p>　　The objective

25、 of this work is to study the interaction cement–superplasticizer by measuring the fluidity of the cement paste in order to select the compatible superplasticizer with the given cement.</p><p>　　The term com

26、patibility characterizes the interaction between the cement and the superplasticizer which offers high fluidity with low saturation dosage and without important fluidity loss. If these performances are not observed, the

27、couple cement and superplasticizer may be marked as incompatible. In addition to this, the effect of increasing the replacement rate of some mineral admixtures on the variation of the cement paste fluidity is examined.&l

28、t;/p><p>　　2. Experimental methods</p><p>　　2.1. Materials</p><p>　　Two types of cement are used; the first one is provided from Chlef cement factory (Algeria) CEM II 42.5, named C1 an

29、d containing 10% of limestone powder. The second one is provided from Zahana cement factory (Algeria) CEM II 42.5, named C2 and containing 15% of natural pozzolan. The physico-chemical and mineralogical characteristics o

30、f these cements are shown inTable 1. Two superplasticizers are used at various dosages to improve the grout fluidity with 40% mass content; SP1 based on polynaphtha</p><p>　　2.2. Mixes production</p>

31、<p>　　The fluidity of the paste is evaluated according to the type of the cement, the superplasticizer and its dosage, the mineral admixture and its replacement rate as well as the W/C ratio.Table 2includes two sets

32、 of paste based on cements C1and C2 containing 10% of limestone powder and 15% of natural pozzolan respectively and are considered as control. The fluidity of the paste was assessed for higher replacement rate of these m

33、ineral admixtures ranging from 15%, 20% and 25% for limestone powder wi</p><p>　　The binder was mixed with water for various W/C ratio; 0.35, 0.4 and 0.45. Several dosages of each superplasticizer were used

34、in the range of 0.4%, 0.6%, 0.8%, 1.0%,1.2%, 1.5% and 2.0 %</p><p><b>　　Table 1</b></p><p>　　Characteristics of materials used</p><p><b>　　.</b></p>&

35、lt;p><b>　　Table 2</b></p><p>　　Mix proportions for the pastes used in testing.</p><p>　　2.3. Test procedures</p><p>　　The pastes were made in Hobart type mixer with a

36、 capacity of 5 l, and using two different speeds (low and high). The procedure used in all test was as follows: a dry cement and mineral admixture were firstly mixed at low speed for 1 min, then 2/3 part of water was add

37、ed and the paste was mixed for 2 more minutes at low speed; finally, 1/3 part of water and superplasticizer were added and the paste was mixed for 2 more minutes at high speed. To study the rheological behavior of cement

38、 with the pr</p><p>　　3. Results</p><p>　　The results of various cement paste obtained by the combination of the two types of cements with and without adding mineral admixture and the two types

39、of superplasticizer show a clear improvement of the fluidity according to the superplasticizer dosage and the W/C ratio.</p><p>　　3.1. Cement type effect</p><p>　　By using the two cements C1 and

40、 C2 to make a cement paste with W/C ratio of 0.4 and containing various dosages of superplasticizer SP1 and SP2, the results obtained for the flow time at 5 min and the fluidity loss are illustrated inFigs. 2 and 3. It i

41、s to be noted that C1 cement has a better fluidity and low saturation dosage of about 0.8% compared with 1% for that of C2 cement when using SP1. Moreover, C1 cement generates a loss of fluidity less important than that

42、of C2 cement. The later prese</p><p>　　As shown inFig. 2, C1 cement with limestone powder provides a very fluid mixture with superplasticizer SP1 based on PNS. For W/C ratio of 0.4, the flow time reaches a m

43、inimal value of 69 s corresponding to only 0.8% of SP1. Contrary to superplasticizer SP2 based on PRM, the fluidity is deteriorated even for strong dosage and remains higher than 93 s. C2 cement containing natural pozzol

44、an has an opposite behavior compared to C1 cement where its fluidity has a high efficiency with SP2 superplastic</p><p>　　Fig. 3illustrates the difference between the flow times relative to 5 and 60 min with

45、 respect to superplasticizer dosage. This fluidity loss disappears with the increase of superplasticizer dosage especially for C1 cement which has a constant fluidity loss beyond 1.5% for SP2 superplasticizer and slightl

46、y less significant for SP1. Similar behavior was observed for C2 cement, where the fluidity loss decreases with the increase of SP2 dosage but remains higher for SP1. Cement with limestone powder</p><p>　　3.

47、2. Saturation dosage</p><p>　　From the curves illustrating the variation of flow time according to the dosage of the superplasticizer, the saturation dosage was determined for all couples of cement–superplas

48、ticizer and is presented inTable 3. It can be concluded that the saturation dosage of superplasticizer decreases according to the water–cement ratio. Superplasticizer SP2 presents a very good compatibility with the two t

49、ypes of cement, contrary to SP1, which presents an almost total incompatibility. Limestone powder addit</p><p>　　3.3. Superplasticizer type effect</p><p>　　The choice of the superplasticizer typ

50、e has a great importance to obtain the most stable fluidity of the paste. By using two superplasticizers; SP1 and SP2 with C1 cement made with W/C ratio of 0.4.Fig. 4shows that the saturation dosage varies from 0.8 to 1.

51、2% for SP1 and SP2 respectively. Similarly, there was no loss of fluidity observed beyond the saturation dosage for SP2 which justifies its compatibility with this type of cement. On the other hand,the results illustrate

52、d in Fig. 5confirm tha</p><p>　　3.4. W/C ratio effect</p><p>　　The cement paste fluidity is very affected by the amount of mixing water, for this reason the fluidity was tested for several W/C r

53、atio. The results presented inTable 3show that superplasticizer SP1 remains incompatible for all W/C ratios, suggesting a notable loss of the fluidity after 1 h from the first contact with water. The fluidity of the mixt

54、ure made with C1 cement and SP2 superplasticizer clearly improves at 5 min with the increase of W/C ratio as illustrated in Fig. 6. It is noted that </p><p>　　3.5. Mineral admixture effect</p><p&g

55、t;　　When the replacement rate of the limestone powder increases from 10% to 15%, 20% and 25% in C1 cement, the fluidity of the paste keeps close values for all replacement rates and seems to be more influenced for low W/

56、C ratio. On the other hand, the loss of fluidity appears much influenced by the content of limestone powder present in the cement. This loss increases remarkably for 15% replacement rate and low W/C ratio as it is illust

57、rated in Fig. 8. Furthermore, the limestone powder has a benefic</p><p>　　4. Discussion</p><p>　　The fluidity of the cement paste is related to the cement hydration and chemical interactions in

58、the cement paste system and can be affected by the combination of cement type and chemical admixture, mineral admixture or water–cement ratio. This fluidity depends of the dispersing performances of superplasticizer whic

59、h is proportional to its adsorption amount on the compound of the cement paste.</p><p>　　5.References</p><p>　　[1] Prince W, Ladnef ME, Aitcin PC. Interaction between ettringite and a polynaphth

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78、al of high performance concrete: effect of ultra fine particles. Cem Concr Res 1998;28(5):687–97.</p><p>　　[21] Yahiaa A, Tanimurab M, Shimoyama Y. Rheological properties of highly flowable mortar containing

79、 limestone filler-effect of powder content and W/C ratio. Cem Concr Res 2005;35:532–9.</p><p>　　礦物摻合料的綜合效應(yīng)與強塑劑混合水泥漿的流動性</p><p><b>　　摘 要：</b></p><p>　　新混凝土通常包含幾個有機物和礦物外加劑

80、，能與水泥的各種成分反應(yīng)，并給硬度和可加工性帶來問題。在目前的研究中，石灰石水泥(C1)和火山灰水泥(C2) 與兩種類型的強塑劑一起被用來生產(chǎn)水泥漿;SP1基于萘系高效減水劑 (PNS);SP2基于樹脂類三聚氰胺(PRM)。流體椎體實驗檢查以下因素對流動性的影響即水泥的類型、強塑劑的類型和用量，類型以及水灰比(W / C)。這項工作的結(jié)果表明石灰石水泥相對飽和火山灰水泥在一小時后顯示出一個高流動性和低損耗性。強塑劑SP1與包含高含量C3

81、A或高堿含量C2的水泥混合時表現(xiàn)出的親和力較低。同時，石灰石粉末被發(fā)現(xiàn)是最好的礦物外加劑，能代替部分水泥，它在稀釋效應(yīng)中表現(xiàn)出了更好的流動性。</p><p>　　關(guān)鍵詞：水泥，石灰石粉末，天然火山灰，強塑劑</p><p><b>　　1、介紹</b></p><p>　　目前,出現(xiàn)在水泥行業(yè)的新材料確實上是增加礦物外加劑的使用，能替代部分水

82、泥，并降低碳酸氣體的排放,降低水泥成本和改善一些技術(shù)要求。為適應(yīng)強塑劑和水泥的適應(yīng)性和共存性，高性能混凝土是用低水灰比制作的。能使提高混凝土的穩(wěn)定性和可加工性。混凝土中添加強塑劑時,某些水泥有時會出現(xiàn)一些不兼容的問題，包括不規(guī)則固化和易性損失。解決這問題的主要方法找到最有效的強塑劑,能夠最大限度的減少水量有更好的可加工性、清水混凝土流動性。一些礦物外加劑的摻入，如高爐礦渣、粉煤灰、硅灰或天然火山灰可使膠結(jié)材料之間的交互作用更復(fù)雜,因此需

83、進一步考慮選擇較好的強塑劑。</p><p>　　強塑劑分子在水化階段有較高的吸附性，因為其中每一個靜電帶電細菌都帶有靜電排斥力和高凝聚性。同時,水泥漿中的鈣礬石的形成降低了流動性。每有一個可溶堿含量對流動性和流動性的損失,就能發(fā)現(xiàn)Na2O相當于0.4 - -0.5%的含量。在這個堿含量中,最初的流動性最大，流動損失也最小。</p><p>　　紐鮑爾等人指出，強塑劑能使水泥的流動性變?nèi)酰?/p>

84、這表明強塑劑會使水泥粒子分離。當新的強塑劑開發(fā)后，水泥和強塑劑的交互作用能夠使流動性急劇變化并根據(jù)水泥和強塑劑產(chǎn)生一定強度。</p><p>　　有專家指出，可以減少強塑劑的含量，水泥的替代量減少到70%，這樣10%的強塑劑就能得到相同的可加工性。結(jié)果證實，強塑劑吸附性取決于C3A和可溶性堿的硫酸鹽水泥的含量。這表明，粉煤灰的摻入使混凝土減少強塑劑的需要，與混凝土相比只作為水泥的一種粘結(jié)劑。另一方面，有學(xué)者觀察到

85、高流動性的硅酸鹽混合到水泥中時，強塑劑的含量從0.5%變化到3%。強塑劑為某些混合物的組成提供了親和性，它可與其他礦物外加劑相替換。同樣，有學(xué)者發(fā)現(xiàn)，水泥漿的流動性的減少是由于填料的引入。</p><p>　　強塑劑 (C-SP)的親和性可以用來測量流漿時間。一些研究人員提出，水泥漿流動性的結(jié)果通常是由一條曲線說明的，系統(tǒng)根據(jù)強塑劑的用量獲得的曲線的類型提出了三個重要點作為控制強塑劑流變行為的研究，表示如下:&l

86、t;/p><p>　　強塑劑添加到飽和時，它并不能提高流動性，只會延遲水泥凝結(jié)時間。</p><p>　　飽和劑量時，其流體的流動性減小。本文會介紹流動性的一些條件。流動性降低的兩個相關(guān)曲線在5和60分鐘;它可以表示這兩個時期的特性，即較低的強塑劑。這項工作的目的是研究強塑劑的交互作用，通過測量水泥漿的流動性來選擇強塑劑與水泥。水泥和強塑劑的交互作用提供了高流動性和低飽和性，降低不重要的流動損

87、失。如果沒有發(fā)現(xiàn)這些現(xiàn)象,水泥和強塑劑可以標記為不相容的。此外，一些礦物外加劑的增加引起水泥漿流動性的變化。</p><p><b>　　2、試驗方法</b></p><p><b>　　2.1 材料</b></p><p>　　使用兩種類型的水泥：第一個水泥廠(阿爾及利亞)杰姆II 提供名叫C1和含有10%的石灰粉；第二

88、個水泥廠(阿爾及利亞)杰姆II 提供名叫C2和含有15%的天然火山灰。這些水泥的物理化學(xué)特征如表1所示。使用兩個強塑劑在不同劑量上能改善漿液流動性;SP1基于萘系高效減水劑 (PNS);SP2基于樹脂類三聚氰胺(PRM)。為了檢查這些礦物外加劑的流動性和水泥與這些強塑劑的兼容性，使用了兩種類型的礦物摻外加劑;用石灰粉和天然火山灰為原材料制造這兩個水泥。通過整合各種外加劑,檢查流動性在不同劑量強塑劑下的變化。這些礦物外加劑的特點表現(xiàn)在表1

89、。</p><p><b>　　2.2 混合生產(chǎn)</b></p><p>　　流動性評估是根據(jù)水泥的類型、強塑劑及其用量、礦物外加劑及其替代率以及W / C比值。如表2</p><p><b>　　表1材料特征.</b></p><p><b>　　表 2混合比例.</b>&l

90、t;/p><p><b>　　包含10%的石灰粉</b></p><p>　　包含15%的天然火山灰C2.</p><p>　　和C2包含10%的石灰粉和15%的天然火山灰分別和被認為是控制。膏的流動性高評估這些礦物摻合料的替代率從15%、20%和25%的石灰石粉水泥C1和20%和25%的天然火山灰水泥C2。礦物摻合料的替代率是計算考慮起源水泥的礦

91、物摻合料的數(shù)量(C1和C2)。粘結(jié)劑與水混合了各種W / C比值,0.35、0.4和0.45。幾個每個強塑劑的劑量范圍中使用了0.4%,0.6%,0.8%,1.0%,</p><p><b>　　2.3 測試步驟</b></p><p>　　低速混合2分鐘后,增加了1/3的一部分水和強塑劑,再高速混合2分鐘。為研究流變與強塑劑,試驗由測量水泥漿流時間(11 - 13)

92、。本設(shè)備在圖1所示,石油工業(yè)很長一段時間來衡量膨潤土或水泥漿的流動性。為此，采用該測試可測量流動時間并研究水泥漿的流變特性。測試在測量后需要將水泥漿通過一個直徑5毫米的開口容器。這個時間是31.5秒。流動時間的測量能使評價水泥漿的流動性;這次的時間越長,水泥漿粘性越高,若時間越短,水泥漿越趨近于液體。流動時間以5和60分鐘后與水接觸。飽和時的劑量被認為是強塑劑的用量超過這個粘性5分鐘的流動性。流動時間之間的差值表示其流動損失。</

93、p><p><b>　　3. 結(jié)果</b></p><p>　　上述結(jié)果獲得的各種水泥膠結(jié)物分兩種類型,在沒有添加礦物外加劑和這兩種類型的強塑劑時顯示出強塑劑用量和W / C比值對流動性的影響。</p><p>　　3.1 水泥種類的影響</p><p>　　通過使用兩個水泥C1和C2，改變W / C和強塑劑SP1和SP2的

94、劑量,流動結(jié)果在5分鐘時間內(nèi)的流動損失如圖所示。需要指出,C1水泥有更好的流動性和低飽和性，大約為0.8%,遠低于1%的C2水泥。此外,C1水泥產(chǎn)生的損失比C2水泥少。這種強塑劑在用量超過1.2%時仍有點效果。</p><p>　　如圖2所示,C1水泥用灰?guī)r粉顯示出了流體混合物與強塑劑混合后的現(xiàn)象，其中W / C比值為0.4。流動時間達到最小值時對應(yīng)于SP1的比值只有0.8%。基于SP1與強塑劑SP2的摻入,較多

95、劑量仍會對流動性產(chǎn)生影響。C2含有天然火山灰水泥有一個相反的行為相比,C1水泥的流動性與SP2強塑劑效率高。這證明了</p><p>　　圖 1. 馬什錐用于測量水泥漿的流動性.</p><p><b>　　強塑劑劑量 %</b></p><p>　　圖2. 各種水泥漿的流動時間變化在5分鐘根據(jù)強塑劑用量(W/C = 0.4).</p&g

96、t;<p>　　圖3.各種水泥失去流動性5至60分鐘(W/C = 0.4).</p><p>　　水泥的類型有很大的影響。強塑劑與水泥的吸附表明出混凝土的和易性較高。圖3展示了不同流動時間下強塑劑用量的變化。這種流動性損失與強塑劑用量的增加成一定的比例,尤其是對C1水泥具有更好的流動作用。再拿C2水泥做相同的比較，其流動性損失減少，而SP2用量增加,但仍高于SP1。水泥和石灰粉(C1)的流動性損失仍

97、然是溫和低劑量的影響因素。另一方面,與天然火山灰水泥(C2)相比，一個強塑劑能使大劑量SP1保持其持續(xù)的流動性。</p><p><b>　　3.2. 飽和計量</b></p><p>　　從曲線的變化說明流動時間是根據(jù)強塑劑的用量而變化的,所有飽和劑量的測定結(jié)果已在表3給出。由此可以得出結(jié)論,強塑劑的飽和劑量會根據(jù)水灰比降低。</p><p>

98、;　　表3結(jié)果各種水泥糊劑的飽和劑量和兼容性.</p><p>　　飽和劑量(C: compatible, I: incompatible).</p><p><b>　　強塑劑劑量 %</b></p><p>　　圖4. 流的變化時間各種強塑劑用量 (水泥C1, W/C = 0.4).</p><p>　　上述兩種類型

99、的水泥的結(jié)果與其相反,這是一個幾乎完全不相容的情況。石灰粉會有助于減少一些不相容的情況,特別是對于替換率高于15%的情況下,因此添加石灰粉或天然火山灰水泥能使飽和度和劑量增加。</p><p>　　3.3 強塑劑種類的影響</p><p>　　強塑劑分子在水化階段有較高的吸附性，因為其中每一個靜電帶電細菌都帶有靜電排斥力和高凝聚性。同時,水泥漿中的鈣礬石的形成降低了流動性。每有一個可溶堿含

100、量對流動性和流動性的損失,就能發(fā)現(xiàn)Na2O相當于0.4 - -0.5%的含量。在這個堿含量中,最初的流動性最大，流動損失也最小。</p><p><b>　　強塑劑劑量%</b></p><p>　　圖5. 流的變化時間各種強塑劑用量 (cement C2, W/C = 0.4).</p><p>　　強塑劑用量的增加表明高劑量的一些強塑劑可能

101、減少糊流動性,確認過度的負面影響強塑劑內(nèi)容觀察到幾個位點(15、16)。在相同的背景下,這種強塑劑的流動性損失相當大的證明其不兼容,特別是C2水泥。</p><p>　　3.4. 水灰比的影響</p><p>　　低速混合2分鐘后,增加了1/3的一部分水和強塑劑,再高速混合2分鐘。為研究流變與強塑劑,試驗由測量水泥漿流時間(11 - 13)。本設(shè)備在圖1所示,石油工業(yè)很長一段時間來衡量膨潤