Effect of Ether-Typed Polycarboxylate Superplasticizer on the Adsorption, Rheology and Concrete Properties

2022 ◽  
Vol 905 ◽  
pp. 320-324
Author(s):  
Yun Hui Fang ◽  
Zhan Hua Chen ◽  
Xiao Fang Zhang ◽  
Zhi Jun Lin ◽  
Hao Chen ◽  
...  

This article disclosed the influence of acid-ether ratio, n(SH)/n(IPEG), and n(APS)/n(IPEG) on adsorption and fluidity performance. The optimum synthetic parameters of acid-ether ratio, n(SH)/n(IPEG) and n(APS)/n(IPEG) were 0.5, 0.35 and 0.05, respectively. The rheology fitting equation was τ= 719.55γ+ 1834.54. And the correlation coefficient was 0.9843. The cement paste conformed to the law of pseudoplastic fluid. The preferred PCE-11 had excellent performance in freshly mixed and hardened concrete.

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1611
Author(s):  
Gintautas Skripkiūnas ◽  
Asta Kičaitė ◽  
Harald Justnes ◽  
Ina Pundienė

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.


2012 ◽  
Vol 487 ◽  
pp. 43-47
Author(s):  
Sheng Hua Lv ◽  
Di Li ◽  
Qiang Cao

A polycarboxylate superplasticizer (PCs) was synthesized by copolymerization of allyl polyoxyethylene ethers (APE), acrylic acid (AA), sodium methylallyl Sulfonate (SMAS) and ethyl acrylate (EA). The effect of functional groups and branch chain on PCs properties was investigated by the test of fluidity of cement paste, retardation performance and Zeta potential of cement particles. The results showed that carboxylic groups and ethyl ester groups can improve water reducing ratio and fluidity of cement paste, and the sulfonic groups has an important contributiion to retardation performance of PCs.


2007 ◽  
Vol 7 (24) ◽  
pp. 3918-3926 ◽  
Author(s):  
Ercan Ozgan ◽  
Ali Ozturk

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Gökhan Kaplan ◽  
Hasbi Yaprak ◽  
Selçuk Memiş ◽  
Abdoslam Alnkaa

The use of mineral admixtures and industrial waste as a replacement for Portland cement is recognized widely for its energy efficiency along with reduced CO2 emissions. The use of materials such as fly ash, blast-furnace slag or limestone powder in concrete production makes this process a sustainable one. This study explored a number of hardened concrete properties, such as compressive strength, ultrasonic pulse velocity, dynamic elasticity modulus, water absorption and depth of penetration under varying curing conditions having produced concrete samples using Portland cement (PC), slag cement (SC) and limestone cement (LC). The samples were produced at 0.63 and 0.70 w/c (water/cement) ratios. Hardened concrete samples were then cured under three conditions, namely standard (W), open air (A) and sealed plastic bag (B). Although it was found that the early-age strength of slag cement was lower, it was improved significantly on 90th day. In terms of the effect of curing conditions on compressive strength, cure W offered the highest compressive strength, as expected, while cure A offered slightly lower compressive strength levels. An increase in the w/c ratio was found to have a negative impact on pozzolanic reactions, which resulted in poor hardened concrete properties. Furthermore, carbonation effect was found to have positive effects on some of the concrete properties, and it was observed to have improved the depth of water penetration. Moreover, it was possible to estimate the compressive strength with high precision using artificial neural networks (ANN). The values of the slopes of the regression lines for training, validating and testing datasets were 0.9881, 0.9885 and 0.9776, respectively. This indicates the high accuracy of the developed model as well as a good correlation between the predicted compressive strength values and the experimental (measured) ones.


1996 ◽  
Vol 26 (11) ◽  
pp. 1619-1627 ◽  
Author(s):  
Osman N. Oktar ◽  
Harun Moral ◽  
Mehmet A. Taşdemir

2018 ◽  
Vol 33 (4) ◽  
pp. 932-937 ◽  
Author(s):  
Yan He ◽  
Xiong Zhang ◽  
Yaning Kong ◽  
Xiaofu Wang ◽  
Liangliang Shui ◽  
...  

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