scholarly journals Sulphate attack Resistance of Geo-polymer Concrete made with Partial Replacement of Coarse Aggregate by Recycled Coarse Aggregate

2019 ◽  
Vol 8 (12) ◽  
pp. 112-117 ◽  
Keyword(s):  
Compressive Strength ◽  
Magnesium Sulphate ◽  
Coarse Aggregate ◽  
Sodium Sulphate ◽  
Partial Replacement ◽  
Polymer Concrete ◽  
Sulphate Attack ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Time Period

The primary intent of this paper is to study replacement of coarse aggregate with RCA of M40 grade concrete in different proportions such as 0%,10%, 20%, 30% and 40% and also to collate the results of geo-polymer concrete made with recycled coarse aggregates(GPCRCA) with geo-polymer concrete of natural coarse aggregate(GPCNA) and controlled concrete of respective grade. Geo-polymer concrete (GPC) is observed to be more resistant towards sulphate attack, with both in (CA) and (RCA) to a replacement of 30%, when it is compared with the similar grade of controlled concrete(CC). The durability of the concrete cubes are analyzed by immersing in 5% concentration solutions for a time period of 15, 45,75 and 105 days, The change of weight and compressive strength towards resistance is evaluated . Results stipulated that Geo-polymer concrete is highly resistant to Sodium sulphate and Magnesium sulphate.

scholarly journals Effect of Recycled Coarse Aggregate and Bagasse Ash on Two-Stage Concrete

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 556
Author(s):  
Muhammad Faisal Javed ◽  
Afaq Ahmad Durrani ◽  
Sardar Kashif Ur Rehman ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Material ◽  
Strength Reduction ◽  
Recycled Aggregate ◽  
Two Stage ◽  
Conventional Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates

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.

scholarly journals Mechanical Properties of Geopolymer Concrete Made With Partial Replacement of Coarse Aggregate by Recycled Aggregate

2019 ◽  
Vol 9 (1) ◽  
pp. 2301-2304 ◽  
Keyword(s):  
Mechanical Properties ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates

Construction is the one the fast growing field in the worldwide. There are many environmental issues connected with the manufacture of OPC, at the same time availability of natural coarse aggregate is getting reduced. Geopolymer binder and recycled aggregates are promising alternatives for OPC and natural coarse aggregates. It is produced by the chemical action of inorganic molecules and made up of Fly Ash, GGBS, fine aggregate, coarse aggregate and an alkaline solution of sodium hydroxide and sodium silicate. 10 M sodium hydroxide and sodium silicate alkali activators are used to synthesis the geopolymer in this study. Recycled aggregates are obtained from the construction demolished waste. The main focus of this work is to find out the mechanical properties of geopolymer concrete of grade G40 when natural coarse aggregate(NCA) is replaced by recycled coarse aggregate in various proportions such as 0%, 10%, 20%, 30%,40% and 50% and also to compare the results of geopolymer concrete made with recycled coarse aggregates(RAGPC) with geopolymer concrete of natural coarse aggregate(GPC) and controlled concrete manufactured with recycled aggregates(RAC) and controlled concrete of natural coarse aggregates(CC) of respective grade. It has been observed that the mechanical properties are enhanced in geopolymer concrete, both in natural coarse aggregate and recycled coarse aggregate up to 30% replacement when it is compared with the same grade of controlled concrete.

scholarly journals Strength and abrasion performance of recycled aggregate based geopolymer concrete

2021 ◽  
Author(s):  
Asfaw Mekonnen LAKEW ◽  
Mukhallad M. AL-MASHHADANI ◽  
Orhan CANPOLAT
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
Splitting Tensile Strength ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Recycled Coarse Aggregate ◽  
One Year

This experimental work evaluated geopolymer concrete containing fly ash and slag by partial replacement of natural coarse aggregate (NCA) with recycled coarse aggregate (RCA) to manufacture environmental-friendly concrete. The proportion of recycled aggregates considered consists of 10%, 20%, 30%, and 40% of the total coarse aggregate amount. Also, a steel fiber ratio of 0.3% was utilized. The mechanical properties and abrasion resistance of fly ash/slag-based geopolymer concrete were then assessed. Majorly, the mechanical strength of the concrete samples decreased by the increase of RCA content. The geopolymer concrete with 40% RCA gave 28.3% lesser compressive strength and 24% lower splitting tensile strength than NCA concrete at one year. Also, the flexural strength of concrete specimens was reduced by 35% (from 5.34MPa to 3.5MPa) with the incorporation of 40% RCA. The incorporation of 30% RCA caused 23% and 22.6% reduction in compressive strength at 56 days and one year, respectively. The flexural and splitting tensile strength of the specimens was not significantly reduced (less than 10%) with the inclusion of a recycled coarse aggregate ratio of up to 30%. Furthermore, the abrasion wear thickness of every concrete sample was less than 1mm. RCA inclusion of 20% produced either insignificant reduction or better strength results compared to reference mixtures. As a result, it was considered that the combination of 0.3% steel fiber and 20% recycled coarse aggregate in fly ash/slag-based geopolymer concrete leads to an eco-friendly concrete mix with acceptable short and long-term engineering properties that would lead to sustainability in concrete production and utilization sector.

Finite Element Analysis of Compressive Strength of Recycled Coarse Aggregate-Filled Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 331-334
Author(s):  
Jing Li ◽  
Zhen Liu ◽  
Xian Feng Qu ◽  
Chong Qiang Zhu ◽  
Yuan Zhang
Keyword(s):  
Finite Element ◽  
Compressive Strength ◽  
Mechanical Model ◽  
Coarse Aggregate ◽  
Geometric Model ◽  
Element Analysis ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Concrete Blocks ◽  
Simulation Results

In order to study prism compressive strength of recycled coarse aggregates-filled concrete, recycled coarse aggregates of particle size for 40-80mm were made from abandoned brick and concrete blocks. 4 groups of recycled coarse aggregates-filled concrete prism objects were made, and the compressive strength of the specimens were done. Using the finite element analytical software(ANSYS) , the stress nephogram and fractured condition of recycled coarse aggregate-filled concrete were obtained after the establishment of the geometric model, calculational model and mechanical model. The results showed that numerical simulation results were good agree with the actual experimental results.

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.

Research on Self-Compacting Concrete Made with Recycled Aggregate

2013 ◽  
Vol 639-640 ◽  
pp. 399-403
Author(s):  
Ai Guo Zhou ◽  
Jian Yin ◽  
Wei Min Song ◽  
Yi Chi
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Self Compacting Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Mineral Additive ◽  
Binder Ratio ◽  
Water Binder Ratio

It is studied the effect of binder quantity, water binder ratio on properties of self-compacting concrete made with recycled coarse aggregates. It can be prepared C50 self-compacting concrete made with recycled coarse aggregate by adjusting send proportion, binder quantity, and mixing mineral additive. For example, when the binder quantity is 600 kg/m3, water binder ratio is 0.28, the flexural strength and compressive strength at 28 days of self-compacting concrete made with recycled coarse aggregates are 9.07 MPa and 68.47 MPa respectively.

scholarly journals Eco-Friendly Asphalt Approach for the Development of Sustainable Roads

2020 ◽  
Vol 1 (3) ◽  
pp. 97-111
Author(s):  
Soleen Jaber Ahmad Al-Hasan ◽  
R. Balamuralikrishnan ◽  
Motasem Altarawneh
Keyword(s):  
Los Angeles ◽  
Impact Test ◽  
Civil Engineering ◽  
Coarse Aggregate ◽  
Road Construction ◽  
Partial Replacement ◽  
Sieve Analysis ◽  
Test Results ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates

Currently, various types of recyclable materials are used in civil engineering applications. One of the future challenges in the civil engineering field facing sustainability and the bulk utilization of waste materials without affecting the performance of the product related to the civil engineering field. Presence of bulk amounts of disposed and demolished materials including aggregates and undecomposed recycled polymers can be recycled. The main aim of reducing environmental impact and also reduction in the cost. Present research focusing on recycled polymers as partial replacement of bitumen in addition to recycled coarse aggregate in different percentages are investigated for its feasibility used in road construction. To achieve the objectives of the current research, 6 batches of bituminous samples were prepared and each case considered three samples for repeatability. The first batch is considered as a control sample without adding Recycled Coarse Aggregates (RCA) and recycled polymer. The second batch consists of 15% partial replacement of bitumen using polymer without recycled aggregate. Remaining batches 3 to 6 were 15% partial replacement of bitumen with polymer and partial replacement of coarse aggregates using recycled coarse aggregate say 25%, 50%, 75%, and 100%. Each batch was tested by reliable and standard tests in order to determine the most efficient mix (batch). The testing methods followed in this investigation are sieve analysis test, impact test, Los Angeles test, penetration test and marshal test. The results of sieve analysis test showed that the fineness modulus value for RCA equals to 4% with uniform graded graph. The specific gravity test results showed that RCA specific gravity is 2.61 which indicates that RCA is considered as coarse grained soils. Moreover, the Impact test for RCA equals 9.3%. In addition, the result for Los Angeles for RCA value is 19.07% and comparing it with the standard and it should be less than 30% is suitable for road construction. Furthermore, penetration test results of 15% partial replacement of bitumen using polymer showed that the average value equals 58 mm compared to 63.7 mm for bitumen without polymer. Finally, the result obtained from the Marshall Stability test showed that batch 5 partial replacement of bitumen 15% using polymer and the partially replaced normal coarse aggregate 75% with RCA gives better results in all aspects. A fruitful conclusion from this study is to follow the approach of utilization of recycled coarse aggregate along with recycled polymers in road construction. Doi: 10.28991/HEF-2020-01-03-01 Full Text: PDF

scholarly journals Performance of Concrete Mixes Containing TBM Muck as Partial Coarse Aggregate Replacements

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6263
Author(s):  
Ala Abu Abu Taqa ◽  
Mohamed Al-Ansari ◽  
Ramzi Taha ◽  
Ahmed Senouci ◽  
Ghaleb M. Al-Zubi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Statistical Analysis ◽  
Coarse Aggregate ◽  
Partial Replacement ◽  
Sem Images ◽  
Edx Analysis ◽  
Coarse Aggregates ◽  
Na Ions ◽  
Compressive And Flexural Strengths ◽  
Metro Project

This study investigated the potential utilization of the TBM muck obtained from the Gold Line of the Doha Metro Project as a partial replacement of coarse aggregates in concrete mixes. First, the TBM muck particles were screened to coarse aggregate standard sizes. Then, concrete mixes were prepared using 0%, 25%, 50%, and 75% TBM muck replacement of coarse aggregates. The compressive and flexural strengths were determined for all mixes at 28 and 56 days. Moreover, the results obtained were validated using EDX analysis and SEM images. A t-statistical analysis did not show a significant impact of TBM muck usage on the compressive strength results of the concrete mixes. However, another t-statistical analysis showed that TBM muck replacement of coarse aggregates had adversely affected the flexural strength results. The EDX analysis indicated the presence of Na+ ions, which can replace the Ca2+ ions in the C-S-H gel, cause discontinuities of it, and hence reduce the strength at later ages. Finally, the SEM images showed that the ettringite and carbon hydroxide (C-H) contents in the mixes with TBM muck were higher than that of the control mix, while the C-S-H gel was less in such mixes.

scholarly journals Strength Performance of Concrete containing Date Seeds as Partial Replacement of Coarse Aggregates under the Exposure of NaCl and Na2SO4

2020 ◽  
Vol 1 (3) ◽  
pp. 206-212
Author(s):  
Adnan Ahmed ◽  
Sajjad Ali Mangi ◽  
Arslan Wali Muhammad ◽  
Naseer Ul Din
Keyword(s):  
Compressive Strength ◽  
Construction Material ◽  
Sodium Sulphate ◽  
Partial Replacement ◽  
Plain Water ◽  
Mixed Solution ◽  
Test Results ◽  
Strength Performance ◽  
Coarse Aggregates ◽  
Normal Water

The strength performance of the concrete structures is of great importance in the field of Civil Engineering. Concrete is the most prevalent and an artificially made construction material all over the world. Concrete is used for the construction of bridges, dams, abutments, and many other hydraulic structures. These structures remain in seawater throughout their service life. As seawater contains a lot of salts, composed of chlorides and sulphates and many other reactive elements. These chloride and sulphates attack on the concrete and cause deterioration of structure. Therefore, the aim of this study was to investigate the strength performance of concrete containing Date Seeds (DS) exposed to Sodium Chloride (NaCl) and Sodium Sulphate Na2SO4. In this study we have replaced the Coarse Aggregates with Date Seeds (DS) by different percentages of weight i.e. (CA:DS)%, (100:0)%, (98:2)%, (97:3)% and (96:4)%. The constant water cement ratio was used in all mixes i.e. 0.5. Workability, Density, and compressive strength were examined by casting 48 standard cubes of 100mm size, and exposure to the NaCl and Na2SO4 Solution for curing at 7 and 28 days. Test results demonstrated that workability first increase at 2% replacement but then decreases as replacement increases. The results of Density and Compressive Strength of Cubes cured in plain water and in mixed solution of NaCl and Na2SO4 were compared. It was observed that the replacement of coarse aggregate with date seeds was increases workability of concrete. Density and compressive strength of cubes cured in plain water decreases to a small extent. For Compressive Strength, it was observed at 28 days, that the Compressive Strength of cubes placed in normal water for curing have greater values as compare to the cubes placed in the salt solution.

scholarly journals Carbonization Durability of Two Generations of Recycled Coarse Aggregate Concrete with Effect of Chloride Ion Corrosion

2020 ◽  
Vol 12 (24) ◽  
pp. 10544
Author(s):  
Chunhong Chen ◽  
Ronggui Liu ◽  
Pinghua Zhu ◽  
Hui Liu ◽  
Xinjie Wang
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Chloride Ion ◽  
Total Porosity ◽  
Recycled Concrete ◽  
Carbonation Depth ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Carbonation Resistance ◽  
Two Generations

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.

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