scholarly journals Development and Performance Assessment of the High-Performance Shrinkage Reducing Agent for Concrete

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Hyung Sub Han ◽  
Jong Kyu Kim ◽  
Yong Wook Jung
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Drying Shrinkage ◽  
Reducing Agent ◽  
Optimal Amount ◽  
Air Content ◽  
Early Strength ◽  
And Performance ◽  
Shrinkage Reducing Agent ◽  
Strength Improvement

To develop a high-performance shrinkage reducing agent, this study investigated several shrinkage reducing materials and supplements for those materials. Fluidity and air content were satisfactory for the various shrinkage reducing materials. The decrease in viscosity was the lowest for glycol-based materials. The decrease in drying shrinkage was most prominent for mixtures containing glycol-based materials. In particular, mixtures containing G2 achieved a 40% decrease in the amount of drying shrinkage. Most shrinkage reducing materials had weaker level of compressive strength than that of the plain mixture. When 3% triethanolamine was used for early strength improvement, the strength was enhanced by 158% compared to that of the plain mixture on day 1; enhancement values were 135% on day 7 and 113% on day 28. To assess the performance of the developed high-performance shrinkage reducing agent and to determine the optimal amount, 2.0% shrinkage reducing agent was set as 40% of the value of the plain mixture. While the effect was more prominent at higher amounts, to prevent deterioration of the compressive strength and the other physical properties, the recommended amount is less than 2.0%.

scholarly journals Effects of Shrinkage Reducing Agent and Expansive Admixture on the Volume Deformation of Ultrahigh Performance Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Su Anshuang ◽  
Qin Ling ◽  
Zhang Shoujie ◽  
Zhang Jiayang ◽  
Li Zhaoyu
Keyword(s):  
Compressive Strength ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Reducing Agent ◽  
Cementitious Material ◽  
Volume Deformation ◽  
Air Content ◽  
Expansive Agent ◽  
Reduction Effect ◽  
Shrinkage Reducing Agent

This paper investigated the influences of shrinkage reducing agent and expansive admixture on autogenous and drying shrinkage of ultrahigh performance concrete (UHPC) containing antifoaming admixture. The shrinkage reducing agent was used at dosage of 0.5%, 1%, and 2% and the expansive admixture was used at dosage of 2% to 4% by mass of cementitious material. The results show that the air content of UHPC increases with the higher addition of shrinkage reducing agent and expansive admixtures. However, the fluidity, compressive strength, and shrinkage of UHPC exhibit a declining tendency. The usage of expansive agent at dosage of 4% significantly reduces the shrinkage of UHPC. The 7-day autogenous shrinkage was decreased by 16.0% and 28-day drying shrinkage was decreased by 29.5%, respectively. Shrinkage reducing agent at dosage of 2% reduced the 7-day autogenous shrinkage by 44.3% and 28-day drying shrinkage by 50.2%. Compared with expansive admixture, shrinkage reducing agent exhibits more efficient shrinkage reduction effect on UHPC.

Research on High Performance Sulfoaluminate Cement Underwater Non-Dispersed Concrete

2011 ◽  
Vol 306-307 ◽  
pp. 956-960 ◽  
Author(s):  
De Cheng Zhang ◽  
Dong Yu Xu ◽  
Xin Cheng
Keyword(s):  
Water Quality ◽  
Compressive Strength ◽  
High Performance ◽  
Raw Materials ◽  
Reducing Agent ◽  
Strength Ratio ◽  
Surrounding Water ◽  
Early Strength ◽  
Effective Water ◽  
Adhesive Performance

Sulfoaluminate cement, non-ionic polyacrylamide and sulfamate high-effective water reducing agent were used as main raw materials to fabricate concrete. The adhesive performance of high performance sulfoaluminate cement underwater non-dispersed concrete and its influence on water quality in surrounding water areas were studied. The compressive strength ratio of concrete cast in water and in air was also determined. The results show that mortar and concrete using non-ionic polyacrylamide as adhesion agent has many advantages such as superior underwater anti-washout properties, little pollution to water quality in the surrounding water areas and obvious early strength. Furthermore, the compressive strength ratio of concrete cast in water and in air is also up to the required standard.

scholarly journals Effects of Shrinkage Reducing Agent and Expanded Cement on UHPC Fluidity, Mechanical Properties, and Shrinkage Performance

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Tingyu Wang ◽  
Jianqing Gong ◽  
Bo Chen ◽  
Xiao Gong ◽  
Hongkui Luo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Setting Time ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Reducing Agent ◽  
Strength Development ◽  
Study Results ◽  
Binder Ratio ◽  
Early Strength ◽  
Shrinkage Reducing Agent

The purpose of this study was to evaluate the effects of a shrinkage reducing agent (SRA) and Portland expanded cement (PEC) on the fluidity, mechanical properties, and shrinkage performance of ultrahigh-performance concrete (UHPC). The results indicated that the fluidity of the fresh UHPC mortar initially decreased and then increases along as a function of SRA dosage. When the dosage of SRA was 1%, the UHPC mortar fluidity was at its minimum. For dosages exceeding 1%, the additional water-binder ratio of the mortar increased, which in turn increased the UHPC fluidity. That is, the SRA delayed the cement hydration and increased the setting time, which is not conducive for early strength development of UHPC. As the SRA dosage was increased (i.e., 0%–2%), the autogenous shrinkage of UHPC decreased significantly such that even a small dosage of about 0.5% SRA was able to effectively reduce drying shrinkage. From the study results, it was also observed that PEC accelerated the loss of fluidity in the fresh UHPC and concurrently promoted the early strength development of UHPC. At 75% PEC content, the strength enhancement effects tended to be stable. This means that although the addition of PEC will potentially increase the autogenous shrinkage of UHPC, it has the positive effect of inhibiting drying shrinkage provided that the PEC dosage is controlled within the 25%–50% range. Furthermore, morphological analyses using a scanning electron microscope (SEM) indicated that an increase in the SRA dosage loosens the UHPC microstructure, with the formation of the hydration products remaining incomplete, thus ultimately causing the UHPC strength to decrease. Overall, the study findings indicated that 2% SRA and 25%–50% PEC can effectively reduce the shrinkage of UHPC and are, therefore, recommended as the optimum dosages.

scholarly journals Research on Shrinkage Inhibition Technology of C50 Steel Shell Immersed Tube Self-Compacting Concrete

2022 ◽  
Vol 2160 (1) ◽  
pp. 012020
Author(s):  
Xudong Wu ◽  
Yingjun Peng ◽  
Tao He ◽  
Putao Song
Keyword(s):  
Compressive Strength ◽  
Drying Shrinkage ◽  
Reducing Agent ◽  
Concrete Mixture ◽  
Steel Shell ◽  
Self Compacting Concrete ◽  
Expansive Agent ◽  
Slump Flow ◽  
Compressive Strength Of Concrete ◽  
Shrinkage Reducing Agent

Abstract The effects of shrinkage reducing agent and expansion agent on workability, strength and shrinkage of C50 self-compacting concrete with steel-shell immersed tube were studied. It is found that the expansive agent can increase the 28d compressive strength of concrete and restrain the shrinkage of concrete, but it can reduce the mixture property of concrete, and the shrinkage reducing agent can reduce the 28d compressive strength of concrete, but it can obviously restrain the shrinkage of concrete and improve the performance of concrete mixture. On the basis that the performance of concrete mixture meets the technical index, when the dosage of shrinkage reducing agent is 1.5%, the performance of concrete mixture is the best, and the drying shrinkage rate of 28d is the smallest. At this time, the properties of C50 steel-shell sunk pipe self-compacting concrete are as follows: slump flow 720mm, T50 2s, pour-down time 2s, v-shaped funnel passing time 6s, 28d compressive strength 59.6 MPa, 28d drying shrinkage 135×10−6.

EXPERIMENTAL STUDY ON DURABILITY OF ROOM TEMPERATURE CURING UFC MORTAR

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Haruka Murakami ◽  
Hiromi Fujiwara ◽  
Masanori Maruoka ◽  
Takahumi Watanabe ◽  
Koji Satori
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
High Performance ◽  
Room Temperature ◽  
Bending Strength ◽  
High Performance Concrete ◽  
Drying Shrinkage ◽  
Concrete Repair ◽  
Repair Materials ◽  
Low Salt

In recent years, as structures become higher, larger, and more durable concrete whose compressive strength of the concrete is 150 N/mm 2 or more have been put to practical use. It is for this reason that it is necessary to develop strengthening materials with equal or better performance. Furthermore, the development of high-performance concrete repair materials is carried out because demand to seismic strengthening and repair increases. In this study, considering these circumstances, it was conducted an experimental study with the aim of developing a repair material using room temperature curing UFC (R-UFC). A binder composition preparation of the R-UFC has excellent fluidity under pressure. It was achieved that high-grade thixotropy, high compressive strength, and high bending strength. It can also be sprayed continuously because of its high thixtoropy. It was confirmed that the sprayed thickness was reached to 20mm by one work. Durability of this R-UFC was investigated and it was confirmed the high sulfate resistance, small drying shrinkage and low salt permeability.

scholarly journals Effect of superabsorbent polymer on mechanical properties of cement stabilized base and its mechanism

2020 ◽  
Vol 2 (1) ◽  
pp. 58-68
Author(s):  
Yongsheng Guan ◽  
Zhixiang Zhang ◽  
Xiaorui Zhang ◽  
Junqing Zhu ◽  
Wen Zhou ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Static Pressure ◽  
Mercury Intrusion Porosimetry ◽  
Drying Shrinkage ◽  
Internal Curing ◽  
Hydration Products ◽  
Mercury Intrusion ◽  
Dry Shrinkage ◽  
Strength Improvement ◽  
Cement Stabilized Base

Abstract Superabsorbent polymers (SAPs) are cross-linked polymers that can absorb and retain large amounts of water. In recent years, a growing interest was seen in applying SAPs in concrete to improve its performance due to its efficiency in mitigating shrinkage. This paper presents findings in a study on effect of SAPs on performance of cement-treated base (CTB), using the experience of internal curing of concrete. CTB specimens with and without SAPs were prepared and tested in the laboratory. Tests conducted include mechanical property testing, dry shrinkage testing, differential thermal analysis, mercury intrusion porosimetry and scanning electron microscope testing. It was found that 7-day and 28-day unconfined compressive strength of CTB specimens with SAPs was higher than regular CTB specimens. 28d compressive strength of CTB specimens with SAPs made by Static pressure method was 5.87 MPa, which is 27% higher than that of regular CTB specimens. Drying shrinkage of CTB specimens with SAPs was decreased by 52.5% comparing with regular CTB specimens. Through the microstructure analysis it was found that CTB specimens with SAPs could produce more hydration products, which is also the reason for the strength improvement.

scholarly journals INVESTIGATIONS ON THE RELATIONSHIP BETWEEN POROSITY AND STRENGTH OF ADMIXTURES MODIFIED HIGH PERFORMANCE SELF-COMPACTING CONCRETE

2016 ◽  
Vol 22 (4) ◽  
pp. 520-528 ◽  
Author(s):  
Beata ŁAŹNIEWSKA-PIEKARCZYK
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Total Porosity ◽  
Self Compacting Concrete ◽  
Research Results ◽  
Air Content ◽  
New Generation ◽  
The Relationship ◽  
Viscosity Modifying Admixture

The influence of a type of new generation: superplasticizer (SP), anti-foaming admixture (AFA) and viscosity modifying admixture (VMA) on the air-content, workability of high performance self-compacting concrete (HPSCC) is analyzed in the paper. The purpose of this study was to examine the influence of type of the admixtures on porosity of HPSCC in the aspect of the compressive strength. The research results indicated that type of admixtures and its combina­tions result in different strengths of HPSCC, regardless of the total porosity characteristics of HPSCC.

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