Influence of polymer treatment on strength and water absorption capacity of recycled aggregate concrete

2017 ◽  
Vol 8 (2) ◽  
Keyword(s):  
Water Absorption ◽  
Absorption Capacity ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Water Absorption Capacity ◽  
Aggregate Concrete

scholarly journals Los Angeles index and water absorption capacity of crushed aggregates

2020 ◽  
Vol 15 (1) ◽  
pp. 65-78
Author(s):  
Mohammed Abed ◽  
Rita Nemes
Keyword(s):  
Los Angeles ◽  
Water Absorption ◽  
High Performance Concrete ◽  
Absorption Capacity ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Aggregate Concrete ◽  
Crushed Aggregate

Abstract The mechanical and physical properties of the crushed aggregate have been studied. The properties of crushed aggregate, which produced from recycled aggregate concrete is not discussed in the literature yet despite it could be a choice in some circumstances like in case of demolishing the structures that already constructed by recycled aggregate concrete. Twenty-two types of self-compacting high-performance concrete made by coarse natural aggregate and coarse recycle concrete aggregate have been crushed and their properties have been studied. The main findings of the present study that, the Los Angeles index and water absorption of crushed aggregate is affected by the coarse recycled concrete aggregate dosage in its parent concrete, as well as, incorporating cement replacing materials in parent concrete help to enhance the abrasion resistance of crushed aggregate.

scholarly journals Effects of Imposed Damage on the Capillary Water Absorption of Recycled Aggregate Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Gao ◽  
Zhiming Ma ◽  
Jianzhuang Xiao ◽  
Fuan Li
Keyword(s):  
Absorption Coefficient ◽  
Water Absorption ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Capillary Absorption ◽  
Capillary Water ◽  
Aggregate Concrete ◽  
Capillary Water Absorption ◽  
Freeze Thaw ◽  
Loading Level

Capillary water absorption of concrete is closely related to its pore structure, permeability, and durability. This paper intensively investigates the effects of imposed damage, including freeze-thaw damage and loading damage, on the capillary water absorption of recycled aggregate concrete (RAC). Freeze-thaw cycle test, loading test, and the experiment of capillary water absorption were carried out, respectively. The results demonstrate that the addition of recycled coarse aggregate (RCA) results in the increase in the capillary absorption behavior of RAC without imposed damage, and there exists a linear correlation between the behaviors of capillary water absorption and chloride penetration of RAC. The imposed freeze-thaw damage or load damage of RAC boosts with the increase of RCA replacement percentages after suffering the same freeze-thaw cycles or loading level. The imposed freeze-thaw damage and load damage further lead to the increase in the capillary water absorption of RAC, and the capillary absorption coefficient of RAC increases linearly with the increased RCA replacement percentages, after suffering the same freeze-thaw cycles or loading level. Furthermore, capillary absorption coefficient increases linearly with the growth of imposed freeze-thaw damage or load damage degree, which can be used to estimate the capillary absorption behavior of RAC exposed to the extreme environment.

scholarly journals Durability Studies on the Recycled Aggregate Concrete in China over the Past Decade: A Review

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Zhiming Ma ◽  
Qin Tang ◽  
Dingyi Yang ◽  
Guangzhong Ba
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Rapid Urbanization ◽  
Aggregate Concrete ◽  
The Past ◽  
Water Absorption Rate ◽  
Average Water

Since China hosted the Olympic Games in 2008, a mass of construction and demolition (C&D) wastes were produced with the rapid urbanization construction. Recycling the C&D waste into recycled aggregates (RA) is an effective method for reducing the amount of C&D wastes. Many studies on the properties of RA and the durability of recycled aggregate concrete (RAC) were conducted in China over the past decade. Due to the restrictions of various languages, some valuable studies on the durability of RAC are hard to be acquired by the scholars around the world. Therefore, this paper is developed to review the studies on the durability of RAC in China, and the shrinkage behavior, chloride permeability, carbonation behavior, and freeze-thaw resistance of RAC are, respectively, introduced. Considering the waste concrete, bricks, and ceramics used in preparing RA are frequently mixed together in China, this study proposes an index of average water absorption rate to quantify the effects of RA types, quality, and replacement percentages on the durability of RAC. Meanwhile, the relationship between the average water absorption rate of RA and the durability parameters of RAC is established. Finally, the improving methods of RAC durability are introduced, and the RA particle shaping and carbonation modification are emphasized.

Study of Surface Modification of Recycled Aggregate and Interfacial Zone Microstructure of the Concrete

2010 ◽  
Vol 150-151 ◽  
pp. 313-316 ◽  
Author(s):  
Hong Zhi Cui ◽  
Feng Xing
Keyword(s):  
Surface Modification ◽  
Water Absorption ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Hardened Cement ◽  
Interfacial Zone ◽  
Aggregate Concrete ◽  
Optimal Value ◽  
High Concentrations ◽  
Zone Microstructure

Due to most of recycled aggregate (RA) possesses higher water absorption, therefore, the process of mixing recycled aggregate concrete (RAC) is more complex than that of normal aggregate concrete (NAC). In this paper, an organosilicone modifier was used to modify RA to reduce its water absorption. Four mixes of concrete were made up with modified RA at a concentration of 1:1, modified RA at a concentration of 1:2, unmodified RA, and NA, respectively. The water absorption unmodified RA and modified RA was compared, and effect of RA surface modification on the microstructure of the interfacial transition zone (ITZ) between the RA and the hardened cement paste was examined. The investigation results show that a higher concentration of modifier is more effective in reducing the water absorption of RA; and there is an optimal value of modifier concentration, and the use of in high concentrations modifier will adversely affect the integrity of interfacial zone.

scholarly journals Experimental Research on the Wettability of Recycled Aggregate Concrete with Fly Ash

2013 ◽  
Vol 7 (1) ◽  
pp. 232-236
Author(s):  
Yuanchen Guo ◽  
Xue Wang ◽  
Jueshi Qian
Keyword(s):  
Fly Ash ◽  
Moisture Absorption ◽  
Drying Shrinkage ◽  
Absorption Capacity ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Structure Theory ◽  
Replacement Rate ◽  
Aggregate Concrete ◽  
Main Factors

Material adsorption, the reverse process of evaporation diffusion, directly reflects the wettability of materials. Wettability is one of the main factors that affect the drying shrinkage of materials. A device that measures the wettability of recycled aggregate concrete (RAC) with fly ash is proposed in this study based on pore structure theory. The isothermal absorption curve of RAC is examined with different fly ash contents. Results show that as the recycled aggregate replacement rate increases, the moisture absorption capacity of RAC gradually increases. The addition of fly ash improves the porosity of RAC structures and reduces material wettability.

Estimation of Water Absorption Capacity of Hardened Concrete with Recycled Aggregate Based on Experimental Determination

2015 ◽  
Vol 732 ◽  
pp. 411-414 ◽  
Author(s):  
Tereza Pavlů ◽  
Magdaléna Šefflová
Keyword(s):  
Water Absorption ◽  
Negative Impact ◽  
High Water ◽  
Absorption Capacity ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Hardened Concrete ◽  
Water Absorption Capacity ◽  
Demolition Waste

Recycled construction and demolition waste, especially recycled concrete, is able to use as an aggregate for concrete. The high water absorption capacity (WA) of recycled aggregate has a negative impact of concrete mix workability and influences the water-cement ratio. This paper presents results of experimental measurement of WA of recycled aggregate and recycled concrete. Series of concrete samples with various replacement ratios of natural aggregate and recycled aggregate were prepared for this study. The main aim of this study is to analyze the influence of recycled aggregate WA, and mixture ratios on the WA of hardened concrete (HC). Regression model to estimate the WA of hardened concrete is presented.

scholarly journals Evaluating the durability of recycled concrete made of coarse recycled aggregate concrete containing silica-fume and natural zeolite

2020 ◽  
Vol 19 (3) ◽  
pp. 457-473
Author(s):  
Hasan Jalilifar ◽  
◽  
Fathollah Sajedi ◽  
Vahid Razavi Toosi ◽  
◽  
...  
Keyword(s):  
Water Absorption ◽  
Silica Fume ◽  
Natural Zeolite ◽  
Full Scale ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Conventional Concrete ◽  
Aggregate Concrete ◽  
Four Levels

This experimental study evaluates the durability of recycled aggregate concrete (RAC) containing silica-fume (SF) and natural zeolite (NZ). For this purpose, four levels of recycled coarse concrete aggregates (RCA) were replaced with natural coarse aggregates (NCA). To compare the effect of pozzolans, three levels of SF (5%, 10%, and 15%) and three levels of NZ (10%, 20%, and 30%) were replaced with cement. To evaluate the durability of RAC, 28 mixed designs were made and the following were measured: compressive strength (CS), water absorption by immersion (WA by immersion), water absorption by capillary (WA by capillary), electrical resistance (ER), electrical conductivity (EC) and rapid chloride penetration test (RCPT). The results indicated that WA by immersion and WA by capillary of RAC increased with enhanced RCA incorporation. On the other hand, the pozzolanic reaction of 10% of SF and 10% of NZ decreased capillary pores and structural weakness of full-scale RAC. However, due to the internal chemical changes of RAC, contrary to the WA by immersion and WA by capillary, compared to conventional concrete (CC), a lower EC and unchanged ER values of RC100 containing pozzolans were seen. The scanning electron microscopy (SEM) revealed that compared to NZ, a 10% of SF significantly improved the microstructure of full scale RAC.

Performance of Recycled Aggregate Containing POFA as Additives for Cement

2015 ◽  
Vol 802 ◽  
pp. 249-254
Author(s):  
A. Suraya Hani ◽  
Wan Mohd Haziman ◽  
Norwati Jamaluddin ◽  
Nurul Hazarine Zakaria
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Palm Oil ◽  
Construction Material ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Hardened Concrete ◽  
Palm Oil Fuel Ash ◽  
Aggregate Concrete ◽  
The Government

Malaysia has been the largest producer and exporter of palm oil in the world, accounting for 52% of the total world oil in year 2006. The waste disposal problem from palm oil industry was increasing. In addition, the government also facing the problems when forced to allocate more landfill for the disposal of concrete waste. Nowadays, the by-product the palm oil mill has becoming potentially to be utilized as construction material in term as additives for cement. This paper discussed the water absorption and compressive strength of Recycled Aggregate Concrete (RAC) containing Palm Oil Fuel Ash (POFA). There are twelve (12) series of concrete mix containing POFA and recycled aggregate (RA) were used as additives for cement that have been indicated as POFA-0%, POFA-10%, POFA-20%, POFA-30% and RA-0%, RA-50% and RA-100%. The slump test was conducted to determine the performance of fresh concrete. The hardened concrete have been tested its compressive strength and water absorption of POFA-concretes at 7 and28 days of water curing ages. The results revealed that POFA-recycled aggregate concrete has lower water absorption and higher compressive strength comparedto recycled aggregate concrete without POFA. The optimum additional of POFA was 30% for concrete made with 100% natural aggregate (NA) produced higher compressive strength and lower water absorption.

Influence of Water Repellent Surface Impregnation on Water Absorption Properties of Recycled Aggregate Concrete

2011 ◽  
Vol 71-78 ◽  
pp. 5011-5014 ◽  
Author(s):  
Ya Guang Zhu ◽  
Pei Zhen Xu ◽  
Qiu Yi Li ◽  
Chuan Li
Keyword(s):  
Surface Water ◽  
Water Absorption ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Water Repellent ◽  
Capillary Water ◽  
Absorption Properties ◽  
Aggregate Concrete ◽  
Capillary Water Absorption

This paper aimed to investigate the influence of using silane surface water repellent treatment on the capillary water absorption properties of recycled aggregate concrete. In this study, two types of coarse aggregate, natural aggregates and recycled aggregates were used, and the surface water repellent treatment of concrete was produced by brushing 100g/m2 and 200g/m2 of paste. It was found that the silane impregnation depth of recycled concrete was deeper than that of natural concrete, and the surface treatment was more effective in the improvement of capillary water absorption properties of recycled aggregate concrete than the natural aggregate concrete.

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