Properties Evaluation of Repair Mortars Containing EVA and VA/VeoVa Polymer Powders

2017 ◽  
Vol 25 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Tsai-Lung Weng ◽  
Wei-Ting Lin ◽  
Cheng-Hao Li

The repair of damaged structures is a complicated problem in the construction industry and it is no uniform standard for evaluating the effectiveness of repair materials. Two different redispersible polymer powders, ethylene vinyl acetate (EVA) and polyvinyl acetate-vinyl carboxylate (VA/VeoVa), were added in the repair mortars with two water-cement ratios and three polymer-cement ratios. The effectiveness of repair materials was evaluated according to the physical, mechanical properties and micrographs. Testing program includes setting time, drying shrinkage, thermal expansion, compressive strength, tensile strength, flexural strength, bond strength, X-ray diffraction analysis, scanning electron microscopy observation. Test results show that the specimens with VA/VeoVa and w/c of 0.5 have highest compressive strength, tensile strength, flexural strength and bond strength. The specimen with EVA also has higher strength than control one at the age of 28 days. The drying shrinkage deformation of VA/VeoVa specimen is close to the control one. The specimens with VA/VeoVa have lower thermal expansion than EVA specimen when the water-cement ratio is 0.5 and there is no difference between EVA and VA/VeoVa specimens for the water-cement ratio of 0.6. The micrographs show that adding polymer powder can reduce the pore and improve the durability.

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668858 ◽  
Author(s):  
Tsai-Lung Weng

The aim of this study was to evaluate the effects of added polymers on the properties of repair mortars. Two types of polymers, ethylene vinyl acetate and polyvinyl acetate–vinyl carboxylate, were used as a replacement for 3%, 5%, and 8% of the cement (by weight). All tests were conducted using two water–cement ratios of 0.5 and 0.6. The effectiveness of the repair materials was evaluated according to setting time, drying shrinkage, thermal expansion, compressive strength, and bond strength. Specimens containing polyvinyl acetate–vinyl carboxylate at a water–cement ratio of 0.5 presented the highest compressive and bond strength. Specimens containing ethylene vinyl acetate presented strength characteristics exceeding those of the control at 28 days. The drying shrinkage of polyvinyl acetate–vinyl carboxylate specimens was similar to that of the control. At a water–cement ratio of 0.5, the thermal expansion of polyvinyl acetate–vinyl carboxylate specimens was lower than that of ethylene vinyl acetate specimens; however, at a water–cement ratio of 0.6, the thermal expansion was independent of the type of polymer.


2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.


2013 ◽  
Vol 830 ◽  
pp. 435-438
Author(s):  
Hong Xia Wang ◽  
Bo Liu ◽  
Kuang Ping Yuan ◽  
Wu Biao Duan ◽  
Fei Hua Yang ◽  
...  

The paper introduces a kind of foaming plaster with main raw material of α- gypsum, which is produced by utilizing the chemical reaction principles H2O2 was decomposed. Meanwhile,study the changes of density,flexural strength and compressive strength of plaster material performance with the additives in different ratio. The result showed that water-cement ratio, H2O2 foaming agent and water temperature all affect the performance of the foaming plaster.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 590 ◽  
Author(s):  
Zengshun Chen ◽  
Yemeng Xu ◽  
Jianmin Hua ◽  
Xu Wang ◽  
Lepeng Huang ◽  
...  

Graphene oxide (GO) has been widely used as an additive due to its numerous unique properties. In this study, the compressive strength, flexural strength and elasticity modulus of concrete containing 0.02 wt%, 0.05 wt % and 0.08 wt % GO, and its dry shrinkage performance have been experimentally investigated. After the sample preparation, apparatus for compression test and flexural test were used to test the relevant properties of concrete containing GO. The dial indicators were used to measure the shrinkage of samples. The results indicate that GO can considerably improve the compressive strength, flexural strength, and elasticity modulus of concrete at the concrete age of 28 days by 4.04–12.65%, 3.8–7.38%, and 3.92–10.97%, respectively, which are substantially smaller than the increment at the age of 3 d by 5.02–21.51%, 4.25–13.06%, and 6.07–27.45% under a water-cement ratio of 0.35. It was also found that GO can increase the shrinkage strain of concrete. For example, at the age of 60 days, 0.02 wt%, 0.05 wt% and 0.08 wt% GO can increase the shrinkage strain of ordinary concrete by 1.99%, 5.79% and 7.45% respectively under a water-cement ratio of 0.49. The study has advanced our understanding on mechanical and shrinkage behavior of concrete containing GO.


Author(s):  
Adda Hadj Mostefa ◽  
Merdaci Slimane

This work is carried out to investigate the performance of concrete reinforced with plastic fibers obtained locally (bottle waste as fiber). Bottle waste plastic was chosen because it is being thrown after single use and cause environmental problem. One way to recycle wasted bottles plastic is grinded into irregular fiber. Then, it was incorporate with the concrete and tests the performance of the concrete. The study was conducted using cylindrical and rectangular (cube) mold of concrete to investigate the performance of the concrete in term of mechanical properties. In this research, the mechanical properties that were measured are compressive strength, splitting tensile strength and flexural strength. The results revealed that the presence of plastic fiber in concrete will increase the concrete performance, as well as the concrete bond strength is improved and the cracks in the concrete decrease the use of fibers and reduce plastic waste.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1899-1902
Author(s):  
Yan Kun Zhang ◽  
Yu Cheng Wang ◽  
Xiao Long Wu

In this article, the flexural strength of combined aggregate concrete with four kinds of water-cement ratio (0.3,0.35.0.4, 0.45), and six ceramsite replace rate (0%, 20%, 40%, 60%, 80%, 60%) are studied with comprehensive test method. Experiment shows that the ceramsite replace rate of combined aggregate has greater influence on the flexural strength than the water-cement ratio. The flexural strength increases with the increasing of compressive strength, and the formula of the flexural strength and compressive strength of combined aggregate concrete is given.


2020 ◽  
Vol 862 ◽  
pp. 135-139
Author(s):  
Dhabit Zahin Alias Tudin ◽  
Ahmad Nurfaidhi Rizalman

In this study, crumb rubber was used to partially replaced fine aggregate in mortar mixture by 5, 10, 15 and 20 volume percentage (vol%) with untreated and NaOH-treated crumb rubber. There were three (3) different water-cement ratio used which are 0.45, 0.50 and 0.55. Thus, the total number of mixtures was 27. The mortars were tested for flowability, compressive strength, flexural strength and density. Based on the results, higher water cement ratio and percentage of crumb rubber replacement increased the flowability but lowered the density, compressive strength and flexural strength of the rubberized mortar. It was also discovered that the significant effect of water-cement ratio on the fresh and hardened properties of the rubberized mortar was due to the water content in the mixture. Meanwhile, the use of NaOH as treatment to crumb rubber improved the flowability, compressive strength and flexural strength of the rubberized mortar.


In this study effect of water-cement ratio (W/C) on the characteristic properties of multiwalled carbon nano tube reinforced concrete is analyzed. Five concrete mixtures of different water-cement ratio (W/C) with and without carbon nano tubes (CNTs) were prepared. W/C of 0.40, 0.45, 0.48, 0.50 and 0.55 were used while quantity of carbon nano tube (CNT) was fixed at 1% by weight of cement (wbc). Ratio of cement, sand and aggregates was also fixed at 1: 1.76:2.66 in all mixes. For maintaining workability 0.5% polycarboxlate based superplasticizer wbc was added in all mixes.. The workability of carbon nanotube reinforced concrete (CNTC) reduced by 60% and W/C=0.50 was found ideal for slump as well as strength. At this W/C compressive strength for CNTC increased by 7.20%, split tensile strength increased by 25.75% and flexural strength increased by 3.87%.


2013 ◽  
Vol 701 ◽  
pp. 12-16 ◽  
Author(s):  
Mohd Irwan Juki ◽  
Khairunnisa Muhamad ◽  
Mahamad Mohd Khairil Annas ◽  
Koh Heng Boon ◽  
Norzila Othman ◽  
...  

This paper describes the experimental investigation to develop the concrete mix design Nomograph for concrete containing PET as fine aggregate. The physical and mechanical properties were determined by using mix proportion containing 25%, 50% and 75% of PET with water cement ratio (w/c) 0.45, 0.55 and 0.65. The data obtained showed that the inclusion of PET aggregate reduce the strength performances of concrete. All the data obtained were combined into one single graph to develop a preliminary mix design nomograph for PET concrete. The nomograph consist of ; relationship between compressive strength and water cement ratio; relationship between splitting tensile strength water cement ratio; relationship between splitting tensile strength and PET percentage and relationship between compressive strength and PET percentage. The mix design nomograph can be used to assists in selecting the proper mix proportion parameters based on the criteria required.


2014 ◽  
Vol 919-921 ◽  
pp. 1908-1911
Author(s):  
Yan Cong Zhang ◽  
Shao Wen Liu ◽  
Ling Ling Gao

A number of rubber cement concrete specimens that rubber powder dosage different were obtained using same cement, water and fine aggregates, by adjusting the dosage of rubber powder. Then it was used to research the influence of rubber powder dosage on performance of cement concrete by measuring its liquidity, strength and toughness. The results show that: when water-cement ratio was equal and rubber powder replacing the same volume sand, the fluidity of cement concrete almost linear increased with rubber powder dosage increasing. With dosage of rubber powder increasing, compressive strength and flexural strength reduced, but toughness linear growth trend when dosage of rubber powder less 30%.


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