The effects of aggregate type size and content on the behavior of normal and high strength concrete and the relationships between compressive strength flexural strength and fracture energy are discussed The concrete mixtures incorporate either basalt or crushed limestone aggregate sizes of 12 mm 39 h in or 19 mm nbsp …

Both coarse aggregates and fine aggregates are the main constituents of concrete because they not only give the body to the concrete it also have a significant effect on the fresh concrete based on aggregate 39 s shape size texture grading and crushing type Moreover it is proved that aggregate 39 s types has the severe effect nbsp …

Preface The objective of this project of which this report is a part is to provide documentation of concrete carbonation during service life and secondary use This documentation should be used for environmental assessment of concrete buildings and structures and to evaluate the effect of concrete carbonation on the nbsp …

Effect of silica fume on recycled aggregate concrete P Huoth Central Queensland University T G Suntharavadivel Central Queensland University K Duan Central Queensland University ePublications SCU is an electronic repository administered by Southern Cross University Library Its goal is to capture and preserve nbsp …

regarding the performance of PCC pavement with 100 RCA Objectives Objectives of this study were to 1 evaluate the engineering properties of recycled concrete aggregate RCA and portland cement concrete PCC made with that aggregate 2 investigate the effect of RCA and PCC properties on continuous rein …

22 May 2013 The capillary barrier system CBS was constructed using fine sand as the fine grained layer and recycled crushed concrete aggregates as the coarse grained layer Analyses of water diversion along inclined covers with capillary barrier effects Effect of soil suction on slope stability at Notch Hill …

This study evaluates the possibility of measuring the damage of the recycled concrete In this way two conventional concretes with a w c ratio of 0 55 and 0 65 were designed Based on them six recycled concretes with different percentages of replacement of natural coarse aggregates with recycled coarse aggregate 20 nbsp …

For example if the grading of two crushed fines ≤ 0 125 mm coming from the same deposit is altered by classification washing in this case and this is the only variable between two concrete mixes i e the total fines content is kept constant this can have a tremendous effect on the concrete slump flow value see below …

identified the following parameters as important for the deterioration of recycled concrete in contact with water iii grain size water quality defined by pH and CO2 content water flow rate and temperature The experimental conditions were carefully chosen based on preliminary tests evaluating the effect of water pH free nbsp …

High Performance Concrete – Innovation amp Utilization The Effect of Concrete Containing Recycled Concrete Aggregate and Crushed Clay Bricks on Slab under Dynamic Loading …

Based on the background of problem the researcher will described the following research statement 1 How are the comparison between Recycled coarse Aggregate RCA and natural aggregate NCA 2 How is the comparison between Recycled Concrete Aggregate with 0 35 50 and 65 in compressive strength nbsp …

The main objective of this project was to evaluate the effects of using aggregate produced from crushed concrete pavement as a replacement for natural coarse aggregate in pavement mixtures A total of ten different concrete mixtures containing recycled concrete aggregate RCA were designed to meet the nbsp …

1 Aug 2017 The use of crushed concrete aggregate CCA formerly referred to as recycled concrete aggregate RCA is increasing particularly with a recent push towards sustainable sourcing of materials Further research is required to understand the effect of coarse CCA on the mechanical properties and durability nbsp …

IOP Conference Series Materials Science and Engineering PAPER OPEN ACCESS Effects of Elevated Temperature on Concrete with Recycled Coarse Aggregates To cite this article M A Salau et al 2015 IOP Conf Ser Mater Sci Eng 96 012078 View the article online for updates and enhancements Related content …

From the results the conclusions described below have been drawn Key words direct shear test recycled concrete aggregate scale effect box size 1 INTRODUCTION The problem of the increasing amount of con struction waste such as concrete or bricks in addition to the simultaneous depletion of natural resources …

30 Jun 2011 The unhydrated particles of portland cement found in CCA and in all hardened concrete plus the dust created in the crushing process has a beneficial effect by strengthening the bond between the paste and aggregate This makes it possible for Cemstone to remove 2 to 3 of the cementitious content nbsp …

Lot of construction debris are generated during the construction and demolition of any concrete structure like buildings roads bridges etc and sometimes even from catastrophes like wars and earthquakes Discarding these wastes is a very serious problem because it requires huge space for its disposal and very little nbsp …

FINAL February August 2011 Crushed concrete aggregate CCA is granular material manufactured by removing crushing and Deicing Salts Not removed May contribute to steel corrosion in new concrete Oil Not removed Small quantity believed to have no effect Joint Sealant Removed prior to demolition nbsp …

the flow Factors such as availability and transportation costs as well as physical properties that can affect stability and fin ishability influence whether crushed cement concrete or construction aggregates should be used or predominate for a particular end use INTRODUCTION The substitution of crushed cement concrete nbsp …

13 May 2013 The paste mortar attached to the recycled aggregate decreases the quality of the aggregate and needs to be stripped The stripped paste mortar is roughly 20 to 50 in waste concrete but relevant research is very limited In this paper the effects of ground waste concrete GWC powder coming from the nbsp …

DOI 10 1515 sgem 2015 0019 SCALE EFFECT IN DIRECT SHEAR TESTS ON RECYCLED CONCRETE AGGREGATE EMIL SOBÓL WOJCIECH SAS ALOJZY SZYMAŃSKI Warsaw University of Life Sciences – SGGW Faculty of Civil and Environmental Engineering ul Nowoursynowska 159 02 776 Warsaw Poland …

the important properties of CRCA needed to design concrete mixes is water absorption but the heterogeneous nature of CRCA makes it harder to predict the actual amount of water that will be absorbed by CRCA during the mixing process This paper compares the effects of over and underestimation of the water nbsp …

Crushed stone produces much more angular and elongated aggregates which have a higher surface to volume ratio better bond characteristics but require more cement paste to produce a workable mixture The surface texture of aggregate can be either smooth or rough A smooth surface can improve workability yet a nbsp …

If we use 65 of recycled aggregate or above each physical properties will drop greatly However if we limit the portion of recycled aggregate adds to concrete it won 39 t affect each property much Based on the research and experiment test quot the maximum nbsp …

The inferior properties of the recycled concrete aggregate RCA as compared with the natural aggregate are caused by the presence of the porous residual …

The use of recycled concrete aggregate RCA as a road base has lowered costs of road construction while KEYWORDS Recycled concrete aggregate RCA base course leachate pH alkalinity heavy metals However contaminant transport modeling to determine the effects due to soil absorption and dilution have …

Transportation agencies 39 experiences and research studies have shown that recycled concrete aggregate RCA under specific conditions has the potential to produce strong durable materials suitable for use in the highway infrastructure The coarse aggregate portion of RCA has no significant adverse effects on nbsp …

Aggregates are inert granular materials such as sand gravel or crushed stone that along with water and portland cement are an essential ingredient in concrete In general if the water cement ratio is chosen correctly a wide range in grading can be used without a major effect on strength When gap graded aggregate nbsp …

The effect of coarse crushed concrete aggregate on the durability of structural concrete Presented at the 1st International Conference on Construction Materials for Sustainable Future CoMS 2017 Zadar Croatia 19 21st April Abstract The use of crushed concrete aggregates CCA formerly referred to as recycled nbsp …

7 Sep 2012 survey showed that among the 30 state respondents 10 allowed the use of crushed concrete as aggregate of California do not require drums to be washed and this small amount has a negligible effect on old and freshly batched concrete had harmful effects on setting time or compressive strength …

18 May 2011 In this experimental study the effects of the recycled fine recycled concrete aggregate FRA that was manufactured from concrete wastes on the concrete properties were investigated In concrete mixtures 0 10 20 30 40 50 and 100 by weight FRA were used instead of river sand Afterwards unit nbsp …

concrete from crushed concrete but that recycled concrete may be expected to have lower strength than concrete made with similar aggregate not previously used de Juan and Gutiérrez 12 studied the effect of attached mortar content on the properties of recycled concrete aggregate It was observed that the properties of nbsp …

Effects of Using Recycled Conl rete as Aggregate on the Engineering Properties of C€ ncrete JR Sri JRavindrarajah School of Civil Engineering University of Technology Sydney Summary Waste concrete produced from demolition of concrete structures is an alternative source for the production of concrete aggregates nbsp …

8 Feb 2016 quot Coarse aggregates such as crushed rock and gravel make up most of a given concrete volume The mining processing and transportation operations for these aggregates consume large amounts of energy and adversely affect the ecology of forested areas and riverbeds quot A recent paper by a team of nbsp …

recycled asphalt pavement RAP and crushed concrete CC as backfill for mechanically stabilized earth MSE walls The objectives of the research project are reviewed The compaction characteristics of RAP and CC are presented and the effect of compaction on particle breakdown is discussed Tests to evaluate the nbsp …

18 May 2015 materials ISSN 1996 1944 www mdpi com journal materials Article The Effects of Different Fine Recycled Concrete Aggregates on the Properties of Mortar Cheng Chih Fan 1 Ran Huang 2 Howard Hwang 3 and Sao Jeng Chao 4 1 Institute of Materials Engineering National Taiwan Ocean University nbsp …

Fine tuning of concrete recycling processes requires a comprehensive understanding of the overlapping interactions and effects of the various influencing parameters The most important parameters associated with recycled concrete aggregate RCA production that may affect quality and yield include such properties of nbsp …

The scope of the paper is to study and compare the properties of concrete made of coarse recycled concrete aggregates with the properties of conventional concrete made of natural ones In particular the effects of recycled concrete aggregates on long term behaviour of concrete shrinkage and creep are reported nbsp …

30 Nov 2017 Abstract The increasing use of crushed concrete aggregates CCA formerly referred to as recycled concrete aggregates RCA has led to research into the effects of coarse CCA in higher value structural applications Concerns exist regarding the effect on chloride ion ingress which ultimately can cause nbsp …

3 investigated the effects of freeze thaw cycles curing time liquid to solid ratio pH and particle sizes on the leaching behavior of metals leached from RCA materials MATERIALS Two conventional graded aggregate base GAB materials and two recycled concrete aggregate materials were used in the current study …