MECHANICAL PROPERTIES AND SHRINKAGE PROPERTIES OF THE CONCRETE WITH RECYCLED FINE AGGREGATE AND ADMIXTURE

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Yuji Nakata ◽  
Koji Takasu ◽  
Hidehiro Koyamada ◽  
Hiroki Suyama
Keyword(s):  
Compressive Strength ◽  
Pore Volume ◽  
Drying Shrinkage ◽  
High Strength ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Shrinkage Ratio ◽  
Recycled Fine Aggregate ◽  
High Durability ◽  
The Relationship

In Japan, it is forecasted that massive amounts of concrete waste material will be generated in the future as a result of demolition of many buildings, and expansion of the use of recycled aggregate is expected. In this study, it was verified the effect when relatively large amount of admixture is mixed, a combination of recycled fine aggregate of different quality and various admixtures, combination of each admixture in order to realize high strength and high durability by using recycled aggregate. The increase in the drying shrinkage ratio due to the deterioration of the recycled fine aggregate quality was larger than the fluctuation due to the admixture mixing ratio and the drying shrinkage ratio was distributed by forming a group for each quality of recycled fine aggregate. In the relationship between the pore volume and the compressive strength, when evaluated with pore volume of 2 μm or less in both cases, a good linear relationship could be confirmed. The relationship between the pore volume and the drying shrinkage rate was similar. Therefore, it was suggested that compressive strength and drying shrinkage ratio of mortar contained composite recycled fine aggregate and admixture could be predicted by evaluating with the pore volume of 2 μm or less.

scholarly journals Durability and Shrinkage Characteristics of Self-Compacting Concretes Containing Recycled Coarse and/or Fine Aggregates

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Mehmet Gesoglu ◽  
Erhan Güneyisi ◽  
Hatice Öznur Öz ◽  
Mehmet Taner Yasemin ◽  
Ihsan Taha
Keyword(s):  
Coarse Aggregate ◽  
Gas Permeability ◽  
Drying Shrinkage ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Restrained Shrinkage ◽  
Durability Properties ◽  
Recycled Fine Aggregate ◽  
Restrained Shrinkage Cracking ◽  
Fine Aggregates

This paper addresses durability and shrinkage performance of the self-compacting concretes (SCCs) in which natural coarse aggregate (NCA) and/or natural fine aggregate (NFA) were replaced by recycled coarse aggregate (RCA) and/or recycled fine aggregate (RFA), respectively. A total of 16 SCCs were produced and classified into four series, each of which included four mixes designed with two water to binder (w/b) ratios of 0.3 and 0.43 and two silica fume replacement levels of 0 and 10%. Durability properties of SCCs were tested for rapid chloride penetration, water sorptivity, gas permeability, and water permeability at 56 days. Also, drying shrinkage accompanied by the water loss and restrained shrinkage of SCCs were monitored over 56 days of drying period. Test results revealed that incorporating recycled coarse and/or fine aggregates aggravated the durability properties of SCCs tested in this study. The drying shrinkage and restrained shrinkage cracking of recycled aggregate (RA) concretes had significantly poorer performance than natural aggregate (NA) concretes. The time of cracking greatly prolonged as the RAs were used along with the increase in water/binder ratio.

scholarly journals Predicting the drying shrinkage behavior of high strength portland cement mortar under the combined influence of fine aggregate and steel micro fiber

2017 ◽  
Vol 67 (326) ◽  
pp. 119 ◽  
Author(s):  
Zhengqi Li
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Drying Shrinkage ◽  
High Strength ◽  
Fiber Content ◽  
Fine Aggregate ◽  
Aggregate Content ◽  
Normal Strength ◽  
Gardner Model

The workability, 28-day compressive strength and free drying shrinkage of a very high strength (121-142 MPa) steel micro fiber reinforced portland cement mortar were studied under a combined influence of fine aggregate content and fiber content. The test results showed that an increase in the fine aggregate content resulted in decreases in the workability, 28-day compressive strength and drying shrinkage of mortar at a fixed fiber content. An increase in the fiber content resulted in decreases in the workability and drying shrinkage of mortar, but an increase in the 28-day compressive strength of mortar at a fixed fine aggregate content. The modified Gardner model most accurately predicted the drying shrinkage development of the high strength mortars, followed by the Ross model and the ACI 209R-92 model. The Gardner model gave the least accurate prediction for it was developed based on a database of normal strength concrete.

On Properties of Recycled Coarse Aggregate from Repeatedly Recycling Waste Concrete

2011 ◽  
Vol 368-373 ◽  
pp. 2185-2188
Author(s):  
Ping Hua Zhu ◽  
Xin Jie Wang ◽  
Jin Cai Feng
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Recycled Fine Aggregate ◽  
Waste Concrete

The properties of recycled coarsee aggregates from repeatedly recycling waste concrete were determined. In this study, five series of concrete mixtures using coarse and fine natural aggregates were prepared, which have the same objective slump value from 35mm to 50mm and different compressive strengths ranging from 25MPa to 60 MPa. These five concretes were crushed, sieved, washed with water, hot treatmented at 300°C before they were used as recycled aggregates. After that, recycled aggregate concrete (RAC) was produced with an objectively compressive strength of 30MPa, in which the recycled coarse aggregate was used as 30%, 70% and 90% replacements of natural coarse aggregate and recycled fine aggregate as 10%, 20%, and 30% replacements of natural fine aggregate. After that, these recycled concretes were used as second recycled aggregates to produce RAC with the same objectively compressive strength of 30MPa. The physical properties of coarse aggregates including apparent density, water absorption, attached mortar content and crushing value were tested and their mineral characteristics were analyzed. The results showed that the quality of recycled coarse aggregates from twicely recycling waste concrete reached the requirements from structural concrete.

scholarly journals An experimental study on production of high strength non-shrink grout containing fly ash

2021 ◽  
Vol 72 (4) ◽  
pp. 477-485
Author(s):  
Chi Dang Thuy
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Fly Ash ◽  
Drying Shrinkage ◽  
High Strength ◽  
Fine Aggregate ◽  
Expansive Agent ◽  
Chemical Admixture ◽  
The University ◽  
The Given

Cement-based grouts are widely used thanks to its outstanding features such as high workability, non-separation, non-bleeding, easy to fulfill small gaps with complex shapes. This paper descrcibes the first phase of a series of laboratory experiments that examined the ability of production of self - levelling mortar at the University of Transport and Communications. The Portland cement-based grout incorporated superplasticizer, fly ash, fine aggregate, water along with expansion agent to match as closed as possible the given high strength non-shrink grout. The experimental study focused on the performance of non-shrink grouts regarding the flowability, expansion and bleeding, strengths and drying shrinkage of the test grout mixtures. The high range water reducer (HRWR) at dosage of 1% by weight of cement was used as a flowability modifying chemical admixture to prevent water segregation and leads to an increase in compressive strength. The parameter tests consist of water-cement ratios, and fixed dosages of superplasticizer and expansive agent. To examine the flowability of grout mortars, the flow cone test was applied. The flow cone test result indicated that there were three proportional of grouts that can meet the requirement of fluidity. The compressive strength of specimens was tested according to ASTM C349-14. It was concluded that the compositions of grouts at a water-cement ratio of from 0.29 to 0.33 have compressive strengths greater than 60 MPa. The tested specimens using the expansive agent with the dosage recommended by the manufacturer meet the non-shrinkage requirement of a grout. The experimental results have demonstrated the ability of production of high strength non-shrink grouts.

scholarly journals Utilization of Completely Recycled Fine Aggregate for Preparation of Lightweight Concrete Partition Panels

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Yibo Yang ◽  
Baixi Chen ◽  
Weizhen Zeng ◽  
Yanjun Li ◽  
Qiaohui Chen ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Economic Analysis ◽  
Pore Structure ◽  
Cross Section ◽  
Lightweight Concrete ◽  
Drying Shrinkage ◽  
Fine Aggregate ◽  
Curing Process ◽  
Recycled Fine Aggregate ◽  
The Cost

AbstractTo reduce the cost of lightweight concrete (LWC) partition panels and to address recycling concrete waste, this work utilized completely recycled fine aggregate (CRFA) to replace the natural fine aggregate and ceramsite in the preparation of LWC and LWC partition panels. To this end, an autoclave-free curing process and an air-entraining agent were used to prepare the CRFA-LWC. The workability, compressive strength, drying shrinkage, and pore structure of the CRFA-LWC and the performance of the CRFA-LWC partition panels were then investigated. The results show that the optimal ratio of the CRFA to the cement is 2.2 for the lightweight concrete, and the optimal panel cross section is a rounded rectangular one. All the pores in the CRFA-LWC have a diameter of smaller than 0.17 mm, and the diameter of 89% of them is less than 0.05 mm. In order to satisfy the drying shrinkage requirements stipulated by Chinese code JC/T 169-2016, the CRFA-LWC should be cured for at least 10 days. The economic analysis concludes that the material cost of CRFA-LWC is 40% lower than that of the autoclaved ceramsite concrete. In addition, utilizing CRFA in lightweight concrete can ease the shortage of natural aggregate.

Experimental Investigation for the Influence of Recycled Aggregate Replacement Content on Tension-Compression Strength

2015 ◽  
Vol 744-746 ◽  
pp. 1412-1415 ◽  
Author(s):  
Zong Ming Jia ◽  
Qing Han ◽  
Ming Hao Liu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Splitting Tensile Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Recycled Fine Aggregate ◽  
Strength Formula

Designing recycled concrete mixture proportion of different recycled coarse and fine aggregate replacement content by pulp content ,then testing compressive strength and splitting tensile strength. The text results show that: With the increasing of recycled aggregate content , the compressive strength and splitting tensile strength of recycled aggregate concrete trended to decrease. Compared to recycled coarse aggregate, recycled fine aggregate impact on the properties of recycled concrete is greater. Establishing the compressive strength and splitting tensile strength formula of recycled concrete based on a lot of experimental results.

Experimental Study on the Fundamental Characteristics of Different Parent Recycled Concrete Fine Aggregates

2013 ◽  
Vol 368-370 ◽  
pp. 1080-1085 ◽  
Author(s):  
Yong Jun Qin ◽  
Lei Li ◽  
Aihemaiti Yibulayin ◽  
Guang Tai Zhang ◽  
Rui Liang
Keyword(s):  
Concrete Strength ◽  
High Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Strength Concrete ◽  
Recycled Fine Aggregate ◽  
Fine Aggregates ◽  
Different Types ◽  
Overall Performance

Recycled aggregate performance vary with different native concrete strength and use environment. Recycled fine aggregate was obtained after the primary concrete was broken and screened. According to Recycled coarse aggregate for concrete and mortar (GB/T 25176-2010), the physical properties of the different types of recycled fine aggregate were analyzed, in addition, determine the classification. The results shows that the properties of recycled fine aggregate all meet the level and they are vary by strengths of its maternal primary concrete and using environments. The overall performance of fine aggregate of high strength primary concrete is the best, followed by the low strength concrete and the moderate strength concrete.

Optimization of HSC Compressive Strength by Taguchi Method

2012 ◽  
Vol 253-255 ◽  
pp. 572-575
Author(s):  
Seyed Hamid Hashemi ◽  
Abed Soleymani
Keyword(s):  
Compressive Strength ◽  
Taguchi Method ◽  
High Strength ◽  
Cementitious Material ◽  
Fine Aggregate ◽  
Supplementary Cementitious Material ◽  
High Durability ◽  
Main Effect ◽  
Large Application ◽  
Method Factors

High strength concrete (HSC) has large application because of good performance and high durability. Optimizing mix proportions has main effect on the compressive strength of HSC. In this paper, optimizing mix proportions are investigated by Taguchi method, factors of water to cementitious material ratio (W/C), fine aggregate to total aggregate ratio (FI/AG), silica fume as supplementary cementitious material and cementitious material content were selected at three levels. After testing L9 orthogonal array and analyzing results by Taguchi method, the best optimized mix levels were predicted by Taguchi. Then optimum mix was constructed and tested. It was concluded Taguchi forecast is true about optimized mix levels.

scholarly journals Engineering of composite materials made of epoxy resins modified with recycled fine aggregate

2021 ◽  
Vol 28 (1) ◽  
pp. 276-284
Author(s):  
Kamil Krzywiński ◽  
Łukasz Sadowski ◽  
Magdalena Piechówka-Mielnik
Keyword(s):  
Compressive Strength ◽  
Epoxy Resin ◽  
Cementitious Materials ◽  
Strength Test ◽  
Recycled Aggregate ◽  
Cementitious Composites ◽  
Fine Aggregate ◽  
Recycled Fine Aggregate ◽  
Resin Coating ◽  
Epoxy Resin Coating

Abstract The paper presents studies performed on polymer-cementitious composite made of epoxy resin coating modified with aggregate and cementitious substrate. Epoxy resin is a perfect material that can be used to protect cementitious materials. According to its manufacturer, it can be mixed with fine aggregate. Coarse aggregate made of building demolition wastes is mostly utilized in concrete mixtures or road structures. Fine aggregate is not widely used. Therefore, the novelty of this research was the utilization of recycled fine aggregate (RFA) in epoxy resin coatings. Natural fine aggregate (NFA) was also used as an extender in the coating. The natural aggregate in the coating was partially replaced with recycled aggregate in amounts of 0, 20, 40, 60, 80, and 100% of its weight. Sixteen specimens of polymer-cementitious composites were prepared for the flexural tensile strength test, and thirty-two specimens for the compressive strength test. The macroscale tests were performed after 35 days of curing (28 days – cementitious substrate, and 7 days – epoxy resin). The results show that the epoxy resin coating does not affect the flexural tensile and compressive strength of the analyzed composites. Moreover, the type of aggregate used in the coating does not have a significant impact on the measured properties of polymer-cementitious composites. Economic analysis was performed in order to estimate the cost of the natural and RFAs used in epoxy resin coatings. The calculations show that a higher amount of RFA should be used to increase savings.

Estimation of Compressive Strength of Recycled Aggregate High Strength Concrete Using Ultrasonic Pulse Velocity

2014 ◽  
Vol 605 ◽  
pp. 147-150
Author(s):  
Seong Uk Hong ◽  
Seung Hun Kim ◽  
Yong Taeg Lee
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Recycled Aggregate ◽  
Strength Concrete ◽  
Recycled Coarse Aggregate

This study used the ultrasonic pulse velocity method, one of the non-destructive test methods that does not damage the building for maintenance of to-be-constructed concrete structures using recycled aggregates in order to estimate the compressive strength of high strength concrete structure using recycled coarse aggregate and provide elementary resources for technological establishment of ultrasonic pulse velocity method. 200 test pieces of high strength concrete 40, 50MPa using recycled coarse aggregate were manufactured by replacement rates (0, 30, 50, 100%) and age (1, 7, 28, 180days), and air curing was executed to measure compressive strength and wave velocity. As the result of compressive strength measurement, the one with age of 180day and design strength of 40MPa was 43.69MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 42.82, 41.22, 37.35MPa, and 50MPa was 52.50MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 49.02, 46.66, 45.30MPa, and while it could be seen that the test piece substituted with recycled aggregate was found to have lower strength than the test piece with natural aggregate only, but it still reached the design strength to a degree. The correlation of compressive strength and ultrasonic pulse velocity was found and regression analysis was conducted. The estimation formula for compressive strength of high strength concrete using recycled coarse aggregate was found to be Fc=0.069Vp4.05, R2=0.66

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