scholarly journals PHYSICAL PROPERTIES OF RECYCLED COARSE AGGREGATE CONCRETE MADE OF THE RAW CONCRETE WITH FINISHING MATERIALS : The compressive strength, static modulus of elastisity and drying shringkage of recycled coarse aggregate concrete

Author(s):  
Kei YANAGI ◽  
Yoshio KASAI
2020 ◽  
Vol 12 (24) ◽  
pp. 10544
Author(s):  
Chunhong Chen ◽  
Ronggui Liu ◽  
Pinghua Zhu ◽  
Hui Liu ◽  
Xinjie Wang

Carbonation durability is an important subject for recycled coarse aggregate concrete (RAC) applied to structural concrete. Extensive studies were carried out on the carbonation resistance of RAC under general environmental conditions, but limited researches investigated carbonation resistance when exposed to chloride ion corrosion, which is an essential aspect for reinforced concrete materials to be adopted in real-world applications. This paper presents a study on the carbonation durability of two generations of 100% RAC with the effect of chloride ion corrosion. The quality evolution of recycled concrete coarse aggregate (RCA) with the increasing recycling cycles was analyzed, and carbonation depth, compressive strength and the porosity of RAC were measured before and after chloride ion corrosion. The results show that the effect of chloride ion corrosion negatively affected the carbonation resistance of RAC, and the negative effect was more severe with the increasing recycling cycles of RCA. Chloride ion corrosion led to a decrease in compressive strength, while an increase in carbonation depth and the porosity of RAC. The equation of concrete total porosity and carbonation depth was established, which could effectively judge the deterioration of carbonation resistance of RAC.


2014 ◽  
Vol 578-579 ◽  
pp. 464-468
Author(s):  
Wen Wu Lan ◽  
Rong Fu Zhong ◽  
Bo Lv ◽  
Jing Yan Gan ◽  
Jing Wei Ying

This study examined the compressive behaviors of concrete with artificial sand that mixed with different content of stone powder (SP). Forty-five cubic specimens were prepared with two strength grades and five SP-content. Including 15 specimens (C35) of recycled coarse aggregate (RA) concrete with artificial sand (RCC35), 15 specimens (C45) of recycled coarse aggregate concrete with artificial sand (RCC45) and 15 specimens (C35) of natural aggregate concrete with artificial sand (NC35). The workability of concrete mixture and the compressive strength of the cubic specimens were tested. The results showed that the slump of concrete mixture decreased with the SP-content increased, and the coagulability and water retentivity of the concrete mixture were improved by using stone powder. The compressive strength of the concrete with artificial sand were increased by incorporating stone powder. The optimal SP-content of RCC35 and NC35 is 20%, while RCC45 is 10%.


2011 ◽  
Vol 147 ◽  
pp. 288-292 ◽  
Author(s):  
Yong Taeg Lee ◽  
Seong Uk Hong ◽  
Hyun Suk Jang ◽  
Sang Ki Baek ◽  
Young Sang Cho

National effort to recycle construction waste as structural concrete usage of high economic value is ongoing, but performance rate of recycling is a low-level due to a lack of awareness on the recycled aggregates. Accordingly, the goal of this study was to verify the structural applicability of recycled aggregates. This study compared a compressive strength based on the replacement ratio of natural aggregate and recycled aggregate, and analyzed a correlation of wave velocity due to the increase in compressive strength under the same condition. The 『design standard strength – replacement ratio of recycled coarse aggregate』 was set to total 12 combinations by applying 0, 30, 50, 100[%] replacement ratio of recycled coarse aggregate to 21, 27, 35[MPa] to the design standard strength. During the experiment of fracture strength, strength degradation due to the replacement rate of recycled coarse aggregate did not occur, and it was found that the wave velocity also increased along with an increase in strength due to the age of recycled coarse aggregate concrete.


2013 ◽  
Vol 357-360 ◽  
pp. 1212-1218 ◽  
Author(s):  
Xi Xi He ◽  
Tao Zhang

Recycled coarse aggregate solid concrete bricks were produced by QTY4-40 brick machine with strength grades of MU15-MU30. Compression and flexural strength of solid recycled coarse aggregate concrete brick were investigated. The impact of recycled aggregate on the solid concrete brick mechanical properties and physical properties was analyzed. The relationship between physical properties and strength, density was discussed.


2012 ◽  
Vol 503-504 ◽  
pp. 1112-1115
Author(s):  
Fang Yu ◽  
Can Bin Yin ◽  
Min Jiang

Experimental work for the compressive strength of recycled aggregate concrete was designed. The results indicated that the recycled coarse aggregate (RCA) re-placement ratio has a remarkable influence on the compressive strength of recycled aggregate concrete.the relationships between the compressive strength and themw/mcratio are also different for differentRCA replacement ratios and the developments for the compressive strength of recycled aggregate concrete are not exactly the same as that of normal concrete.


2013 ◽  
Vol 307 ◽  
pp. 395-398
Author(s):  
Bai Liang Yang ◽  
Wei Wang ◽  
Xu Chao Chi ◽  
Wen Hui Bai

The compressive strength development process of recycled coarse aggregate concrete (RCAC) directly affects the safety of the engineering structures, which is an important research topic in the concrete mechanics. According to the statistics of the experimental results, the development mechanism principle of the compressive strength of RCAC gradually increasing with curing time was analyzed. The mathematical property was introduced to reveal the defects of the traditional hyperbolic model of the time-relative compressive strength (TRCS), and to point out that the mathematical nature of the ideal TRCS model should have. A new CES model was presented for TRCS. The mathematical analysis shows that the hyperbolic model is a special case of the CES model, and in another hand the CES model overcomes the defects of the hyperbolic model.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 556
Author(s):  
Muhammad Faisal Javed ◽  
Afaq Ahmad Durrani ◽  
Sardar Kashif Ur Rehman ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  

Numerous research studies have been conducted to improve the weak properties of recycled aggregate as a construction material over the last few decades. In two-stage concrete (TSC), coarse aggregates are placed in formwork, and then grout is injected with high pressure to fill up the voids between the coarse aggregates. In this experimental research, TSC was made with 100% recycled coarse aggregate (RCA). Ten percent and twenty percent bagasse ash was used as a fractional substitution of cement along with the RCA. Conventional concrete with 100% natural coarse aggregate (NCA) and 100% RCA was made to determine compressive strength only. Compressive strength reduction in the TSC was 14.36% when 100% RCA was used. Tensile strength in the TSC decreased when 100% RCA was used. The increase in compressive strength was 8.47% when 20% bagasse ash was used compared to the TSC mix that had 100% RCA. The compressive strength of the TSC at 250 °C was also determined to find the reduction in strength at high temperature. Moreover, the compressive and tensile strength of the TSC that had RCA was improved by the addition of bagasse ash.


Sign in / Sign up

Export Citation Format

Share Document