scholarly journals EXPERIMENTS ON BEAMS WITH RECYCLED CONCRETE USED FINE AGGREGATE OF MELTING SLAG FROM MUNICIPAL SOLID WASTE : Part 4 A study on structures used the recycled aggregate concrete

2002 ◽  
Vol 67 (551) ◽  
pp. 103-109 ◽  
Author(s):  
Reiji TANAKA ◽  
Masafumi KITATSUJI ◽  
Hayato TOKAI ◽  
Yoshiki OHAGA
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Melting Slag

Recycling of Waste Concrete and Fly Ash for Recycled Aggregate Concrete: Fundamental Characteristics Evaluation

2009 ◽  
Vol 620-622 ◽  
pp. 255-258 ◽  
Author(s):  
Cheol Woo Park
Keyword(s):  
Fly Ash ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Recycled Concrete Aggregate ◽  
Aggregate Concrete ◽  
Waste Concrete

As the amount of waste concrete has been increased and recycling technique advances, this study investigates the applicability of recycled concrete aggregate for concrete structures. In addition fly ash, the industrial by-product, was considered in the concrete mix. Experimental program performed compressive strength and chloride penetration resistance tests with various replacement levels of fine recycled concrete aggregate and fly ash. In most case, the design strength, 40MPa, was obtained. It was known that the replacement of the fine aggregate with fine RCA may have greater influence on the strength development rather than the addition of fly ash. It is recommended that when complete coarse aggregate is replaced with RCA the fine RCA replacement should be less than 60%. The recycled aggregate concrete can achieve sufficient resistance to the chloride ion penetration and the resistance can be more effectively controlled by adding fly ash. It I finally conclude that the recycled concrete aggregate can be successfully used in the construction field and the recycling rate of waste concrete and flay ash should be increased without causing significant engineering problems.

scholarly journals Compressive Strength Study on the Freeze-thaw Resistance of Recycled Aggregate Concrete Members

2017 ◽  
Vol 11 (1) ◽  
pp. 270-280 ◽  
Author(s):  
Haicheng Niu ◽  
Yonggui Wang ◽  
Xianggang Zhang ◽  
Xiaojing Yin
Keyword(s):  
Compressive Strength ◽  
Mass Loss ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Replacement Rate ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Surface Scaling

Introduction: Freeze-thaw resistance of recycled aggregate concrete with partial or total replacement of recycled aggregate compared with that of natural aggregate concrete was investigated in this paper. Method: Ninety specimens were fabricated to study the influence of different recycled aggregate replacement ratios on the surface scaling, mass loss, and residual compressive strength after 100 freeze-thaw cycles. Results: The experiment results indicate that the type of recycled aggregate and its replacement ratio have significant effects on the freeze-thaw performance. The cubic compressive strength of recycled aggregate concrete is overall slightly lower than that of normal concrete. After 100 freeze-thaw cycles, the compressive strength decreases and the reduction extent increases with increasing replacement rate of recycled aggregate. The surface scaling of reinforced recycled concrete prisms tends to be more severe with the increase of freeze-thaw cycles. Conclusion: Furthermore, a notable rise in mass loss and the bearing capacity loss is also found as the substitution ratio increases. Under the same replacement rate, recycled fine aggregate causes more negative effects on the freeze-thaw resistance than recycled coarse aggregate.

scholarly journals Compressive performance of 50 MPa strength concrete-filled square and circular tube (CFT) columns using recycled aggregate

2018 ◽  
Author(s):  
Sung-Mo Choi ◽  
Won Ho Choi ◽  
Kangseok Lee ◽  
Jae-Yong Ryoo ◽  
Sunhee Kim ◽  
...  
Keyword(s):  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Steel Pipe ◽  
Strength Development ◽  
Fine Aggregate ◽  
Mixing Ratio ◽  
Compressive Behavior ◽  
Aggregate Concrete ◽  
Cft Column

Recycled aggregate is an environmentally self-sustainable solution that can reduce construction waste and replace natural aggregates. However, there is a disadvantage in concrete such as initial strength drop and long-term strength development. Therefore, the interaction effect of the two materials can be expected by filling the cyclic aggregate concrete in the CFT column. In order to develop a concrete with compressive strength of 50 MPa as a recycled aggregate, we carried out a mixing experiment and fabricated 18 specimens to confirm the compressive behavior of a RCFT (Recycled Concrete Filled Tube) column that can be applied to actual buildings. Variable is the shape and thickness of steel pipe, concrete strength and mixing ratio, and coarse aggregate and fine aggregate are all used as recycled aggregate. The optimum mixing ratio for recycled aggregate concrete to be filled in the CFT filled steel pipe was found through three concrete preliminary mixing experiments. In addition, the compression test of the RCFT column was carried out to observe and analyze the buckling shape of the CFT column. Based on the analysis of the buckling configuration and the experimental data, the load-displacement curves of the specimens were drawn and the compressive behavior was analyzed. 

Shear-Crack Behaviors of Reinforced Full-Recycled Aggregate Concrete Beams

2013 ◽  
Vol 438-439 ◽  
pp. 794-799 ◽  
Author(s):  
Chang Yong Li ◽  
Guang Xin Li ◽  
Wen Jing Shao ◽  
Qi Guo ◽  
Rui Liu
Keyword(s):  
Crack Width ◽  
Concrete Beams ◽  
Shear Crack ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Shear Span ◽  
Shear Cracking

On the basis of experimental results, this paper discusses the shear-crack behaviors such as shear-cracking force and shear-crack width of reinforced full-recycled aggregate concrete beams. The full-recycled aggregate concrete was developed for the sustainable development in civil engineering, in which the coarse aggregate was the recycled aggregate made of abandoned concrete, and the fine aggregate was the machine-made sand. Sixteen beams, six of them without stirrups, were tested with the shear-span ratio varying as 1.5, 2.0 and 3.0, and the ratio of stirrups varying from 0.19% to 0.35%. The results showed that the shear-cracking force of the beam was mainly affected by the shear-span ratio, the width of shear-cracks intersecting stirrups decreased with the increasing ratio of stirrups, but the maximum crack width almost exceeded the limit 0.3mm in the first class environmental condition specified in Chinese code GB50010-2010. Comparing the calculation results by substituting the test parameters of full-recycled aggregate concrete beams into the formula of ordinary reinforced concrete beams, the lower resistance of reinforced recycled concrete beam to shear-cracking, and the larger crack width intersecting stirrups should be noted in the structural design. Based on the test data, the formula for calculating the shear-cracking force and the shear-crack width of reinforced full-recycled aggregate concrete beams are suggested.

Application of Molten Slag Fine Aggregate Concrete Using Superplasticizer

2006 ◽  
Vol 302-303 ◽  
pp. 329-338
Author(s):  
Shuzo Otsuka ◽  
Yoshihisa Nakata ◽  
Takeshi Saito ◽  
Hiroki Takahashi ◽  
Keishi Tobinai ◽  
...  
Keyword(s):  
Molten Slag ◽  
Full Scale ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Significant Difference

With increasing number of melting-solidification plants for the domestic wastes and incineration ashes, the resulting molten slag is now expected as a recycled aggregate for concrete in Japan, while application examples until now are limited to non-loadbearing pre-cast concrete and concrete secondary products. This study deals with a full-scale application of molten slag recycled fine aggregate. Starting with the inspection of monthly variations in quality of molten slag fine aggregate in a plant, construction of a full-scale structure was attempted using the recycled aggregate concrete with a superplasticizer. During construction, pumpability of the recycled concrete was examined and the quality of hardened concrete in the structure was evaluated. It was shown that quality variation of the molten slag fine aggregate during eight months was sufficiently small, and pumpability as well as concrete quality in structure showed no significant difference with those of the ordinary concrete.

scholarly journals Compressive Strength of Concrete with Recycled Concrete Aggregate as Coarse Aggregate and Recycled Paving Block Aggregate as Fine Aggregate Partially Substituted by Recycled Brick Aggregate

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Idi Priyono ◽  
Meiske Widyarti, Erizal
Keyword(s):  
Compressive Strength ◽  
Residential Buildings ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Concrete Mix

An excessive extraction of natural resources for aggregate in concrete mix can caused an environmental degradation.  According to Indonesia ministry of industry in 2017, the use of cement is predicted will reach 84,96 million tons, that can affected the use of aggregate for concrete mix are quadruplet to 250 – 350 million tons. Opimally, the use of recycled material is green method that can reduce an excessive extraction of natural aggregates and keep an environmental sustain. The aim of this study is to obtain recycled aggregate concrete compressive strength and examine recycled aggregate concrete quality in days 3, 7, 28, 35, and 90 along with a proposal of the use of recycled aggregate concrete as a building construction material. This research used experimental method of SNI 03-2834-2002 the standard of normal concrete mix design for f’c 25 MPa then built five types of concrete mix of REC B, REC C, REC D, REC E, and REC F with every types of concrete has four sample are used for compressive strength test. The fine recycled paving block aggregate (RPA) were used partially to substituted a fine recycled brick aggregate (RBA) at 0%, 25%, 50%, 75%, and 100% by weigth. The result of this study showed the mixed concrete REC D with RCA 100%, RPA 50% and RBA 50% in 28 days is generate highest compressive strength than other recycle aggregates concrete mixes. Compressive strength at 28 days in a mix codes REC B, REC C, REC D, REC E and REC F are 18,12 MPa; 18,36 MPa; 19,35 MPa;16,69 MPa; and 16,39 MPa. The results show that it is feasible to replace a natural aggregate entirely by recycled aggregates. With compressive strength over 17 MPa at 28 days, mix codes REC B, REC C and REC D are recommended to use the recycled aggregate concrete for structure of residential buildings but mix codes REC E and REC F aren’t recommended and only allowed for non-structural concrete such as separate wall (SNI 8140:2016). Based on SNI 03-0691-1996 about solid brick concrete (paving block), recycle aggregate concrete with mix code of REC B, REC C, and REC D are able to use on paving block with B quality such as parking lot. While, recycled aggregate concrete with mix code of REC E and REC F are able to use on paving block with C and D quality which used for pedestrian, garden and other use. 

scholarly journals Acoustic Emission Characteristics and Damage Mechanisms Investigation of Basalt Fiber Concrete with Recycled Aggregate

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4009
Author(s):  
Guodong Li ◽  
Li Zhang ◽  
Fengnian Zhao ◽  
Jiaqi Tang
Keyword(s):  
Acoustic Emission ◽  
Coarse Aggregate ◽  
Failure Process ◽  
Basalt Fiber ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Fiber Concrete

This paper presents the compression failure process of basalt fiber concrete with recycled aggregate and analyzes the main factors of basalt fiber and recycled aggregate affecting the compressive strength of recycled concrete. The damage mechanism of recycled aggregate concrete is analyzed by the acoustic emission technique. With the method of acoustic emission (AE) b-value analysis, the evolution and failure process of recycled concrete from the initial defect microcrack formation to the macroscopic crack is studied. Based on the AE clustering analysis method, the damage state of recycled concrete under load grade is investigated. Finally, the failure mode of recycled concrete is explored according to the RA-AF correlation method. The results show that when the concrete reaches the curing age, the strength grade of basalt fiber regenerated coarse aggregate concrete is the highest. The basalt fiber increases the strength of regenerated fine concrete by 4.5% and the strength of coarse concrete by 5%, and reduces the strength of fully recycled aggregate concrete by 6.7%. The b-value divides concrete into three stages: initial damage, stable development of internal damage, and internal damage. The variation of AE energy, count, and event number is related to AE activity and crack growth rate. Matrix cracking is the main damage state of concrete, which is greatly affected by the strength of cement mortar. The load grade of fiber cracking in fully recycled aggregate, recycled fine aggregate, and recycled coarse aggregate concrete is 65, 90, and 85%, respectively. Basalt fiber increases the tensile failure event point of recycled concrete and delays the cracking of recycled concrete under compression. When the load grades of fully recycled fiber, recycled fine aggregate fiber, and recycled coarse aggregate fiber concrete are 65–95, 90–100, and 85–100%, respectively, the tensile failure activity increases.

scholarly journals Experimental Study on the Mechanical Properties and Compression Size Effect of Recycled Aggregate Concrete

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2323
Author(s):  
Yubing Du ◽  
Zhiqing Zhao ◽  
Qiang Xiao ◽  
Feiting Shi ◽  
Jianming Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Size Effect ◽  
Compressive Stress ◽  
Failure Modes ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Substitution Ratio ◽  
The Impact

To explore the basic mechanical properties and size effects of recycled aggregate concrete (RAC) with different substitution ratios of coarse recycled concrete aggregates (CRCAs) to replace natural coarse aggregates (NCA), the failure modes and mechanical parameters of RAC under different loading conditions including compression, splitting tensile resistance and direct shear were compared and analyzed. The conclusions drawn are as follows: the failure mechanisms of concrete with different substitution ratios of CRCAs are similar; with the increase in substitution ratio, the peak compressive stress and peak tensile stress of RAC decrease gradually, the splitting limit displacement decreases, and the splitting tensile modulus slightly increases; with the increase in the concrete cube’s side length, the peak compressive stress of RAC declines gradually, but the integrity after compression is gradually improved; and the increase in the substitution ratio of the recycled aggregate reduces the impact of the size effect on the peak compressive stress of RAC. Furthermore, an influence equation of the coupling effect of the substitution ratio and size effect on the peak compressive stress of RAC was quantitatively established. The research results are of great significance for the engineering application of RAC and the strength selection of RAC structure design.

Study on the Basic Mechanical Properties of Recycled Concrete Hollow Block Masonry

2013 ◽  
Vol 438-439 ◽  
pp. 749-755 ◽  
Author(s):  
Tong Hao ◽  
Dong Li
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Shear Behavior ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Test Results ◽  
Aggregate Concrete ◽  
Mortar Strength ◽  
Hollow Block

By the experimental studying on the basic mechanical properties of recycled concrete hollow block masonry, the compressive and shear behavior of recycled aggregate concrete hollow block masonry under different mortar strength were analyzed. Research indicated that the compressive and shear behavior of recycled aggregate concrete hollow block masonry was similar to that of ordinary concrete hollow block masonry. The normal formula was recommended to calculate the compressive strength of the masonry. The shear strength of the masonry was affected by the mortar strength. The shear strength calculation formula of recycled concrete hollow block masonry was proposed according to the formula of masonry design code. The calculating results were in good agreement with the test results.

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