scholarly journals Shrinkage and Durability Evaluation of Environmental Load-Reducing FRPCM by Using Silicone Oil

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1240 ◽  
Author(s):  
Hyeonggil Choi ◽  
Heesup Choi ◽  
Bokyeong Lee ◽  
Dong-Eun Lee
Keyword(s):  
Cement Mortar ◽  
Silicone Oil ◽  
Reducing Agent ◽  
Fiber Reinforced Polymer ◽  
Environmental Load ◽  
Reduction Mechanism ◽  
Reinforced Polymer ◽  
Expansive Additive ◽  
Strength And Durability ◽  
Shrinkage Reducing Agent

In this study, the shrinkage and durability of environmental load-reducing fiber-reinforced polymer cement mortar (FRPCM) were examined by using silicone oil. The results indicated that the shrinkage can be greatly reduced by adding silicone oil. However, when the silicone oil is added in excess, it affects the strength and durability. Therefore, it is possible to obtain the ECO-FRPCM which gives the effect of reducing the shrinkage and maintaining the strength and durability by adding 3% of silicone oil. From the viewpoint of shrinkage reduction, the use of silicone oil is effective as a substitute for an expansive additive or shrinkage reducing agent used in ECO-FRPCM. Also, by appropriately using silicone oil in combination with an expansive additive or a shrinkage reducing agent, shrinkage can be effectively reduced as compared with the conventional ECO-FRPCM. However, when the silicone oil and the shrinkage reducing agent are used in combination, the shrinkage cannot be efficiently reduced. It is considered that the combination of silicone oil and shrinkage reducing agent influences the mutual shrinkage reduction mechanism, but this needs to be further examined in the future.

Effect of Expansive Additive and Shrinkage Reducing Agent on Plastic Shrinkage of Steam-Cured Mortar

2018 ◽  
Vol 936 ◽  
pp. 207-213
Author(s):  
Sarapon Treesuwan ◽  
Komsan Maleesee ◽  
Shigeyuki Date
Keyword(s):  
Factorial Design ◽  
Setting Time ◽  
High Volume ◽  
Reducing Agent ◽  
Steam Curing ◽  
Initial Setting Time ◽  
Plastic Shrinkage ◽  
Initial Setting ◽  
Expansive Additive ◽  
Shrinkage Reducing Agent

This research is part of the mortar’s plastic shrinkage study. Contents in this article is related to how the Expansive Additive (EX), Shrinkage Reducing Agent (SRA), and Fly Ash (FA) help to reduce and control the shrinkage and to compare the effectiveness of these substances used in the normal curing, i.e., at 30 °C and in the steam curing process by using the factorial design with 3 factors and to be divided into 2 levels. Factors to be studied are the amount of EX, SRA and FA replacement. The test of plastic shrinkage was conducted in accordance with the ASTM C1579-06 standard, placing the strain gauge 0.5 centimeters beneath the surface in the middle of the mold, recording the shrinkage rate starting from the initial setting time for 24 hours. The results showed that, in normal curing, the EX influences the expansion while, in steam curing, the EX and SRA significantly influences the expansion. To add the FA in high volume along with the EX significantly effects the expansion for both the normal and steam curing. Furthermore, the study model and equation for plastic shrinkage of mortar are presented in the form of factor proportion to be considered from the factorial design study basis.

scholarly journals Effects of Shrinkage Reducing Agent and Expansive Additive on Plastic Shrinkage of Mortar at Different Temperatures

2018 ◽  
Vol 206 ◽  
pp. 02002
Author(s):  
Sarapon Treesuwan ◽  
Komsan Maleesee ◽  
Shigeyuki Date
Keyword(s):  
High Temperature ◽  
Setting Time ◽  
Reducing Agent ◽  
Early Age ◽  
Initial Setting Time ◽  
Plastic Shrinkage ◽  
Different Temperatures ◽  
Expansive Additive ◽  
Hot Weather ◽  
Shrinkage Reducing Agent

In the construction, it is inevitable to perform plaster work in hot weather which causes the dehydration and rapid shrinkage on the paste during the early age. This research shows the studies of reducing the plastic shrinkage of mortar during the early age with such additives as the Shrinkage Reducing Agent (SRA), the Expansive Additive (EX), and the Fly Ash (FA) in controlled temperatures at 30°C and 40°C, with relative humidity between 60% and 70% according to the ASTM C1579-06 standard, with the strain gauge installed at 0.5 cm.from the surface. The shrinkage rate was measured starting from the Initial Setting Time and every 10 minutes afterwards for 24 hours. The results show that high temperature effects the cracking and how to use different formulas of additive under different circumstances is considerably important. To use only one additive is not sufficient in high temperature. To use the SRA in addition to the EX enhances better expansion than to use only the EX. Moreover, it is recommended to pay close attention in adding large amount of the FA into mortar with the EX and SRA added which extremely enhances the expansion and potential cracking.

scholarly journals Effects of Shrinkage Reducing Agent and Expansive Additive on Mortar Properties

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Sarapon Treesuwan ◽  
Komsan Maleesee
Keyword(s):  
Compressive Strength ◽  
Reducing Agent ◽  
Early Age ◽  
Alkyl Ether ◽  
Test Results ◽  
Steam Curing ◽  
Plastic Shrinkage ◽  
Compressive Strength Test ◽  
Expansive Additive ◽  
Shrinkage Reducing Agent

This research is to study the effect of mortar mixed with shrinkage reducing agent (polyoxyalkylene alkyl ether type), expansive additive (CaO type), and fly ash (hereinafter “SRA,” “EX,” and “FA,” resp.). Moreover, steam curing was studied to improve the properties of mortar. The plastic shrinkage test was conducted by using the strain gauge embedded at 0.5 cm from the surface according to the ASTM C1579-06 standard within early age followed by the total shrinkage test and compressive strength test. The test results showed that mixing both the EX and SRA increases the plastic enlargement of the mortar during the early age more than using either the EX or SRA solely. The steam curing helps to reduce the plastic shrinkage when the mortar is added with the FA and SRA while adding the EX increases the enlargement compared to the normal curing. When the EX, SRA, and FA are all added to the mortar mixing, great attention should be paid due to the increase of greater enlargement. For the compressive strength view, the steam curing increases the compressive strength in all types of mixture. The steam curing significantly helps increasing the compressive strength of mortar with combination of EX, SRA, and FA. Nevertheless, the XRD and SEM tests explain such enlargement accordingly.

The Influence of Chemical Admixtures on the Autogenous Shrinkage Ultra-High Performance Concrete

2010 ◽  
Vol 452-453 ◽  
pp. 725-728 ◽  
Author(s):  
Jung Jun Park ◽  
Sung Wook Kim ◽  
Gum Sung Ryu ◽  
Kwang Myung Lee
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Pulse Velocity ◽  
Reducing Agent ◽  
Shrinkage Stress ◽  
Early Age ◽  
Ultra High Performance Concrete ◽  
Expansive Additive ◽  
Shrinkage Reducing Agent

Ultra-high performance concrete (UHPC) is a material developing remarkable performance with compressive strength of about 200 MPa and flexural strength of approximately 30 MPa on which research is actively conducted today. However, UHPC is also characterized by a mixing composed of a high specific quantity of binder that is a W/B ratio of about 0.2, which requires to examine the effects of the autogenous shrinkage. Accordingly, this study investigates the effects of the use of expansive additive and water reducing agent on the autogenous shrinkage of UHPC at early age. To that goal, autogenous shrinkage test and ultrasonic pulse velocity (UPV) monitoring are conducted for a mixing of UHPC using expansive additive and shrinkage reducing agent. The experimental results reveal that the autogenous shrinkage of UHPC reduces by 24% for a mix of UHPC adopting both 7.5% of expansive additive and 1% of shrinkage reducing agent compared to the mix without admixture. Furthermore, this mix is seen to compensate the autogenous shrinkage occurring at early age when UHPC develops its largest stiffness in view of the UPV evolution curve. At that time, the shrinkage stress seems to be extremely softened.

scholarly journals Experimental Study on Shear Strengthening of RC Beams with an FRP Grid-PCM Reinforcement Layer

2019 ◽  
Vol 9 (15) ◽  
pp. 2984 ◽  
Author(s):  
Rui Guo ◽  
Lianheng Cai ◽  
Shinichi Hino ◽  
Bo Wang
Keyword(s):  
Evaluation Method ◽  
Cement Mortar ◽  
Effective Strain ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Strengthening Effect ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Reinforced Polymer ◽  
Series Of Experiments

This paper investigates the shear strengthening effect of a number of reinforced concrete (RC) beams strengthened by a reinforcement layer which combines carbon fiber reinforced polymer (CFRP) grid and polymer cement mortar (PCM). A total of ten RC beams, including three types of specimens as Series A and seven kinds of specimens as Series B, were prepared and investigated. The test variables in both series of experiments included various reinforcement ranges and different reinforcement amounts that consisted of CFRP grids’ spacing and cross-section areas. The experimental results suggest that the shear strengthening effect of the CFRP grid-PCM layer for RC beams is obvious and adequate. Meanwhile, better performance is observed if the CFRP grid-PCM reinforcement layer is used for the full sectional reinforcement of RC beams with an I-shaped profile, in contrast to RC beams with reinforcement of the web only. In addition, a new evaluation method based on the effective strain of the CFRP grid is developed to determine the shear capacity of RC beams strengthened by a CFRP grid-PCM layer.

The Mechanical Properties of Polypropylene Fiber Reinforced Polymer Modified Cement Mortar

2013 ◽  
Vol 438-439 ◽  
pp. 283-289
Author(s):  
Huu Feng ◽  
Dan Ying Gao ◽  
Jian Song Yuan
Keyword(s):  
Cement Mortar ◽  
Polypropylene Fiber ◽  
Short Fiber ◽  
Fiber Reinforced Polymer ◽  
Polypropylene Fibers ◽  
Reinforced Polymer ◽  
Waterborne Epoxy ◽  
Mineral Powder ◽  
Polymer Modifier ◽  
Epoxy Emulsion

Combining the effect of polypropylene fibers, such as the decrease of cement base material shrinkage and plastic crack, and the increase of material toughness, with the improvement of polymer on the interface between the fiber and matrix, both polypropylene fibers and polymer modifier were used in the cement mortar at the same time to make more excellent cement mortar materials. The improvement for cement mortar from different length of polypropylene fiber, polymer modifier (waterborne epoxy emulsion), mineral powder and silica ash were studied. Results showed that compared with the short fiber, the long fiber has a more obvious effect on the toughness, the best dosage of which is 0.6 kg/m3; the waterborne epoxy emulsion improved the bonding properties of interface between polypropylene fiber and cement mortar matrix, and then, long fibers improved flexural strength of cement mortar greatly, in terms of short fiber, effect is not manifest; With the increase of mineral powder, all the mechanical index of polypropylene fiber reinforced polymer modified cement mortar were improved and the effect of silica ash was better than that of mineral powder, the optimal replacement ratio were 0.1 and 0.3 respectively.

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