【正文】 made with W/C ratio of . 4shows that the saturation dosage varies from to % for SP1 and SP2 respectively. Similarly, there was no loss of fluidity observed beyond the saturation dosage for SP2 which justifies its patibility with this type of cement. On the other hand,the results illustrated in Fig. 5confirm that C2 cement has an acceptable patibility with superplasticizer SP2 based on PRM,where the fluidity is slightly influenced by the dosage without significant loss beyond 1%. For superplasticizer SP1, the fluidity of the paste made with C2 cement is less important pared with that of C1 cement. It is to be noted that the fluidity obtained is reduced with the increase of the superplasticizer dosage. This indicates that high dosages of some superplasticizers may reduce the paste fluidity, confirming the negative effect of excessive superplasticizer content observed by several works[15,16]. In the same context,the fluidity loss is considerable for this superplasticizer which proves its inpatibility, particularly with C2 cement. . W/C ratio effect The cement paste fluidity is very affected by the amount of mixing water, for this reason the fluidity was tested for several W/C ratio. The results presented inTable 3show that superplasticizer SP1 remains inpatible 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 mixture 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 for high W/C values, the flow time converges towards a unique value for various dosages of superplasticizer. Also,for a dosage higher than %, the flow time preserves nearly the same variation according to W/C ratio. From the results represented inFig. 7, the flow time of the mixture made with C2 cement and SP2 superplasticizer decreases with the increase of W/C ratio. When W/C ratio exceeds , the flow time values are close and remain constant for all superplasticizer . 6 and 7show that the fluidity of the cement paste made with C1–SP2 is more sensitive to the increase of the mixing water than that made with C2–SP2, where the fluidity varies only for low W/C ratio. . Mineral admixture effect 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/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 illustrated in Fig. 8. Furthermore, the limestone powder has a benefic effect on the flow time and does not reveal any loss of fluidity for high W/C . 9illustrates the effect of the presence of the natural pozzolan on the fluidity of C2 cement. When the replacement rate increases from 15% to 20% and 25%, the fluidity of the paste at 5 min remains constant with a little improvement particularly for low W/C ratio. For W/C ratio, the addition of natural pozzolan leads to a considerable loss of fluidity. 4. Discussion The fluidity of the cement paste is related to the cement hydration and chemical interactions in the cement paste system and can be affected by the bination of cement type and chemical admixture, mineral admixture or water–cement ratio. This fluidity depends of the dispersing performances of superplasticizer which is proportional to its adsorption amount on the pound of the cement paste. [1] Prince W, Ladnef ME, Aitcin PC. Interaction between ettringite and a polynaphthalene sulfonate superplasticizer in a cementitious paste. Cem Concr Res 2020。8:17–27. [5] Hanehara S, Yamada K. Interaction between cement and chemical admixture from the point of cement hydration, absorption behavior of admixture and paste rheology. Cem Concr Res 1999。22:1963–71. [9] Sone T, Sarkar SL, Uchikawa H. The influence of cross linked and NSF superplasticizer on the flow properties of blended cement. In: Proceeding of the fourth CANMET/ACI conference on superplasticizers and other chemical admixtures in concrete, Montreal, Canada。rales, S233。thode du coulis. Bulletin desLPC, N161, Maijuin。 1992. p. 115–21. [14] Lessard M, Gendreau M, Baalbaki M, Pigeon M, Aitcin PC. Formulation d’un b233。n233。16(5):45–52. [17] Odler T, Becker T. Effect of some liquefying agents on properties and hydration of Portland cements and tricalcium silicate pastes. Cem Concr Res 1980。28(5):687–97. [21] Yahiaa A, Tanimurab M, Shimoyama Y. Rheological properties of highly flowable mortar containing limestone fillereffect of powder content and W/C ratio. Cem Concr Res 2020。SP2 基于 樹脂類三聚氰胺 (PRM)。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?；炷林刑砑訌娝軇r ,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。同時 ,水泥漿中的鈣礬石的形成降低了流動性。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。另一方面，有學者觀察到高流動性的硅酸鹽混合到水泥中時，強塑劑的 含 量 從 %變化到 3%。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 : 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。它可以表示這兩個時期的特性，即較低的強塑劑。此外，一些礦物外加劑的增加引起水泥漿流動性的變化。SP1 基于萘系高效減水劑 (PNS)。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。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。為研究流變與強塑劑 ,試驗 由測量水泥漿流時間 (11 13)。這個時間是 秒。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。需要指出 ,C1 水泥有更好的流動性和低飽和性，大約為 %,遠低于 1%的 C2 水泥。流動時間達到最小值時對應(yīng)于 SP1 的比值只有 %。 強塑劑 與水泥的 吸附 表明出 混凝土 的 和易性 較 高。水泥和石灰粉 (C1)的 流動性損失仍然是溫和低劑量 的影響因素 。 表 3 結(jié)果各種水泥糊劑的飽和劑量和兼容性 . Cement C1 + superplasticizer SP1 Cement C1 + superplasticizer SP2 Replacement rate of limestone powder % E/C 10 15 20 25 10 15 20 25 (I) (C） 1 (C) (C) (C) (C) ( C ) 1 (C) (I) 1 (I) (C) 1 (C) (C) (C) (C) (C) 1 (I)