scholarly journals Resistance of Acid Attack on Geopolymer Concrete Developed with Partial Replacement of Course Aggregate by Recycled Aggregate

2019 ◽  
Vol 8 (4) ◽  
pp. 12142-12146
Keyword(s):  
Fly Ash ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Acid Attack ◽  
Great Strength ◽  
Conventional Concrete ◽  
Existing Structures ◽  
Binder Material

Geopolymer concrete is one of the major developments in recent years resulting in utilization of fly ash in huge quantities and eventually reducing cement consumption and ultimately reducing emission of greenhouse gases.The geopolymer concrete is produced by using activated fly ash as binder material instead of cement. Geopolymer concrete accomplishes great strength and looks similar to conventional concrete. Recycled coarse aggregate (RCA )which is coming from demolition of construction of old and existing structures has been used in this study. The durability property; acid attack resistance with partial replacement of coarse aggregate by recycled aggregate in geopolymer and conventional concrete for the different composition such as 10, 20, 30 and 40percentage for a period of 15, 45,75 and 105 days has been evaluated. From the results it was observed that in both natural and recycled aggregate of Geopolymer concrete is highly resistant to acids such as sulphuric acid and hydrochloric acid compared to conventional concrete of respective aggregates.

scholarly journals Behavior of Quarry Rock Dust, Fly Ash and Slag Based Geopolymer Concrete Columns Reinforced with Steel Fibers under Eccentric Loading

2021 ◽  
Vol 11 (15) ◽  
pp. 6740
Author(s):  
Rana Muhammad Waqas ◽  
Faheem Butt
Keyword(s):  
Fly Ash ◽  
Concrete Cover ◽  
Steel Fibers ◽  
Structural Behavior ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Fiber Reinforced ◽  
Conventional Concrete ◽  
Source Materials ◽  
Rock Dust

Geopolymer concrete, also known as an earth-friendly concrete, has been under continuous study due to its environmental benefits and a sustainable alternative to conventional concrete construction. The supplies of many source materials, such as fly ash (FA) or slag (SG), to produce geopolymer concrete (GPC) may be limited; however, quarry rock dust (QRD) wastes (limestone, dolomite, or silica powders) formed by crushing rocks appear virtually endless. Although significant experimental research has been carried out on GPC, with a major focus on the mix design development, rheological, durability, and mechanical properties of the GPC mixes; still the information available on the structural behavior of GPC is rather limited. This has implications in extending GPC application from a laboratory-based technology to an at-site product. This study investigates the structural behavior of quarry-rock-dust-incorporated fiber-reinforced GPC columns under concentric and eccentric loading. In this study, a total of 20 columns with 200 mm square cross-section and 1000 mm height were tested. The FA and SG were used as source materials to produce GPC mixtures. The QRD was incorporated as a partial replacement (20%) of SG. The conventional concrete (CC) columns were prepared as the reference specimens. The effect of incorporating quarry rock dust as a replacement of SG, steel fibers, and loading conditions (concentric and eccentric loading) on the structural behavior of GPC columns were studied. The test results revealed that quarry rock dust is an adequate material that can be used as a source material in GPC to manufacture structural concrete members with satisfactory performance. The general performance of the GPC columns incorporating QRD (20%) is observed to be similar to that of GPC columns (without QRD) and CC columns. The addition of steel fibers considerably improves the loading capacity, ductility, and axial load–displacement behavior of the tested columns. The load capacities of fiber-reinforced GPC columns were about 5–7% greater in comparison to the CC columns. The spalling of concrete cover at failure was detected in all plain GPC columns, whereas the failure mode of all fiber-reinforced GPC columns is characterized with surface cracking leading to disintegration of concrete cover.

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.

scholarly journals A Review on Geopolymer RCC Beams made with Recycled Coarse Aggregate

2020 ◽  
Vol 184 ◽  
pp. 01095
Author(s):  
T Srinivas. ◽  
G Abhignya. ◽  
N.V Ramana Rao.
Keyword(s):  
Coarse Aggregate ◽  
Rice Husk Ash ◽  
Concrete Beams ◽  
Raw Materials ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Geopolymer Concrete ◽  
Literature Study ◽  
Conventional Concrete ◽  
Day By Day

In present day scenario, concrete construction is rapidly increasing for different uses and aspects irrespective of the economy and its usage. Due to this imbalanced usage of economy, scarcity of raw materials increasing day by day and environment is getting affected due to manufacturing of cement. This study has been done how to reduce environmental pollution by using different kind of bi product materials in replacement to conventional concrete, which is made up of OPC. The cement can be replaced with fly ash; GGBS, rice husk ash etc, aggregates are being partially replaced with recycled aggregates which come from demolished structures and alkaline liquids such as sodium silicates and sodium hydroxide can be used in concrete, which is called geopolymer concrete. Literature review has been carried out to find the optimum content of aggregates to be replaced and the flexure behavior of the beams is being evaluated. From the literature study, it has been identified that the optimum compressive strength is achieved at 30% replacement of recycled aggregate and ductility natures of both Geopolymer and conventional concrete beams are almost similar.

scholarly journals Structural Behaviour Fly ash and Ferrochrome ash Based Geopolymer Concrete with Recycled Aggregate

2019 ◽  
Vol 8 (4) ◽  
pp. 9329-9335
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Carbon Footprint ◽  
Concrete Beam ◽  
Coarse Aggregate ◽  
Reinforced Concrete Beam ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Geopolymer Concrete ◽  
Structural Behaviour

Recycled aggregates are the construction demolition wastes which can be used in concrete industry to reduce the carbon footprint of the environment. This paper deals with the structural behaviour of reinforced concrete beam made with different percentages of recycled aggregate as coarse aggregate on a novel geopolymer concrete consist of fly ash and ferrochrome ash as binder. Structural behaviour of RCC beam with 10% and 20% recycled aggregate in geopolymer concrete are studied and compared to the 100% natural coarse aggregate. Experimental results revealed that the up to 10% replacement of recycled aggregate can achieve strength equal to control concrete and it can be the recommended percentage of RCA for concrete industry.

scholarly journals Permeation Properties of Geopolymer Concrete Made with Partial Replacement of Recycled Coarse Aggregates

2019 ◽  
Vol 8 (12) ◽  
pp. 2987-2990
Keyword(s):  
Coarse Aggregate ◽  
Environmental Control ◽  
Construction Material ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Similar Time ◽  
Chemical Action ◽  
Coarse Aggregates ◽  
Permeation Properties

Concrete is themost generally used construction material inthe world due to, wonderful durability, straight forward accessibility of its constituent materials, its low price, straightforward formability to any shape, etc. There are many ecological problems connected with the manufacture of OPC, at a similar time accessibility of natural coarse aggregate is additionally changing into scarcity and on the other side, the disposal of C&D wastes is additionally changing into a significant environmental issue . Hence, it is unavoidable to find an alternative material to the existing most resource consuming Portland cement and natural aggregates. GPC is a construction material of innovation concrete which shall be produced by the chemical action of inorganic molecules and made up of fly ash, GGBS, FA, CA, and an alkaline solution of NaOH and Na2SiO3 , plays a significant role in its environmental control of greenhouse effects. The main objective of this paper is to study the permeation properties such permeability, sorptivity etc.,of geopolymer concrete of grade G40 when natural coarse aggregate is replaced with recycled aggregate in different proportions such as 10%, 20%, 30%, and 40% and also to compare the results of geopolymer concrete made with recycled coarse aggregates with geopolymer concrete of natural coarse aggregate and controlled concrete of respective grade. It has been observed that the permeability and sorptivity properties are better 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 concreterespectively.

scholarly journals Partial Replacement of Coarse Aggregate by using Recycled Aggregate

2019 ◽  
Vol 8 (12S) ◽  
pp. 1093-1095
Keyword(s):  
Developing Countries ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Conventional Concrete ◽  
Concrete Mixtures ◽  
Selection Of

The high and rapidly rising cost of cement has made construction expensive in developing countries where cement is commonly used. Tests were conducted in this undertaking research with the selection of necessary materials and information required for the configuration of the blend is collected. Cubes and cylinders were casted with these concrete mixtures and subjected to 7-day, 14-day and 28-day healing and determining their strength. The determined compressive strength and spilt tensile strength was compared with the conventional concrete for percentage replacements of (0%,5%,10%,15%).

scholarly journals Influence of Bentonite on Mechanical and Durability Properties of High-Calcium Fly Ash Geopolymer Concrete with Natural and Recycled Aggregates

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7790
Author(s):  
Rana Muhammad Waqas ◽  
Faheem Butt ◽  
Aamar Danish ◽  
Muwaffaq Alqurashi ◽  
Mohammad Ali Mosaberpanah ◽  
...  
Keyword(s):  
Fly Ash ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Acid Attack ◽  
Aggregate Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Strength And Durability

In this study, bentonite (a naturally occurring pozzolana) was incorporated as a partial replacement (up to 20%) for high-calcium fly ash (HCFA)-based geopolymeric natural aggregate concrete (GNAC) and geopolymeric recycled aggregate concrete (GRAC). The mechanical (compressive strength and splitting tensile strength), durability (chloride migration coefficient, water absorption, and acid attack resistance), and rheological properties (slump test, fresh density, and workability) were investigated. The results revealed that incorporation of bentonite (10 wt % with ordinary Portland cement) showed appreciable improvement in the strength and durability of both the GNAC and GRAC, though its effect is more significant for GRAC than the GNAC.

scholarly journals Performance of Light Weight Concrete with Coconut Shell and Fly Ash

2021 ◽  
Vol 9 (9) ◽  
pp. 1119-1127
Author(s):  
Vani Kulkarni
Keyword(s):  
Fly Ash ◽  
Coarse Aggregate ◽  
Coconut Shell ◽  
Partial Replacement ◽  
Light Weight ◽  
Conventional Concrete ◽  
Concrete Cylinders ◽  
Light Weight Concrete ◽  
Failure Loads ◽  
Cost Of Materials

Abstract: The major factor that affects the housing delivery is high cost of materials for any conventional concrete. This has lead to find an alternative. An attempt has been made to find an alternative by using partial replacement of coarse aggregate by coconut shell aggregate and cement by fly ash. This report provides the information obtained from a literature search. And also provides laboratory experiments on Cement, Sand, Coarse aggregate and Coconut shell. This project is done using partial replacement of coarse aggregate by coconut shell aggregate and cement by fly ash.10 % of fly ash was kept constant as replacement for cement. And Coarse aggregate was replaced by 5%, 10%, 15%, and 20% of coconut shell aggregate.30 concrete cubes of 150x150x150 mm size were casted and 3 cubes were tested after 7 days of curing and 3 cubes were tested after 28 days of curing for each percentage.30 concrete Cylinders of 150x300 mm size were casted and 3 Cylinders were tested after 7 days of curing and 3 Cylinders were tested after 28 days of curing for each percentage.15 concrete Beams of 100X100X500 mm size were casted and 3 beams were tested after 28 days of curing for each percentage. Two models were done using ANSYS Software using the same failure loads from the experimental part. Keywords: Light weight concrete, coconut shell, Fly-ash, experimental.

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.

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