Fracture Parameters of Fly Ash and GGBS Based Geopolymer Concrete

2015 ◽  
Vol 764-765 ◽  
pp. 1090-1094
Author(s):  
Tippabhotla D. Gunneswara Rao ◽  
P. Alfrite ◽  
G. Mallikarjuna Rao ◽  
Mudimby Andal
Keyword(s):  
Fly Ash ◽  
Construction Material ◽  
Bending Test ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Conventional Concrete ◽  
Three Point Bending ◽  
Beam Depth ◽  
New Construction ◽  
Source Materials

Geopolymer concrete (GPC) is a new construction material in which cement is totally replaced by calcined source materials fly ash and GGBS. Geopolymer utilization reduces or eliminates the use of cement whose production produces a lot of carbon dioxide. Usually fly ash as a source material for the geopolymer. The behavior of GPC has to be studied in detail to check its suitability in construction industry. In the present study, the fracture behavior of geopolymer concrete is investigated and compared. Three-point bending test on notched prisms with a/d (notch depth/beam depth) ratios 0.1, 0.15, 0.2 are considered. The values of Critical load, fracture toughness, fracture energy and ductility are presented. The test results of total of 27prisms, 6cubes, 18 cylinders with M30 grade geopolymer concrete and conventional concrete (OPC) of same grade are presented in this paper. The test results indicated that the characteristic length of GPC is about 25% more than that of conventional concrete.

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 Studies on Mechanical properties of High Calcium Fly ash based sustainable Geopolymer concrete

2021 ◽  
Vol 2070 (1) ◽  
pp. 012184
Author(s):  
B Vijaya Prasad ◽  
N Anand ◽  
P D Arumairaj ◽  
M Sanath Kumar ◽  
T Dhilip ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Construction Material ◽  
Sustainable Construction ◽  
Geopolymer Concrete ◽  
Conventional Concrete ◽  
High Calcium ◽  
Major Interest ◽  
High Calcium Fly Ash

Abstract Geopolymer concrete (GPC) is a Sustainable construction material, in which cement is completely replaced by Fly ash as binder. To control emission of CO2 during the production of cement, it is advisable to use alternate sustainable Cementitious material. The development of GPC become a major interest to use for in-situ and precast applications. The present study aims to develop High calcium fly ash based GPC with aid of alkaline liquids such as sodium Hydroxide (NaOH) and Sodium silicate (Na2SiO3). Different molarities i.e 4M, 6M, 8M and 10M are used to develop the GPC under ambient and oven curing process. In the present investigation the Fresh properties of GPC and Mechanical properties such as compressive strength, Tensile strength, Flexural strength and Elastic modulus of GPC are investigated. An increase of alkaline activator in in the mix decreased the workability of GPC. The developed GPC mix of 8M is found to be the optimum for gain in compressive strength. A polynomial relationship is obtained for the mechanical properties of GPC developed under ambient and oven curing. The development cost of GPC can be reduced up to 11.25 to 16.5% as compared with conventional concrete grade of M25.

scholarly journals Study on Effect of Superplasticizer on GGBS Blended Geopolymer Concrete

2019 ◽  
Vol 2 (2) ◽  
pp. p45
Author(s):  
Vahini M. ◽  
K. Manjunatha ◽  
Venkatesh ◽  
Basappa Meti
Keyword(s):  
Fly Ash ◽  
Waste Product ◽  
Embodied Energy ◽  
Geopolymer Concrete ◽  
Strength Parameters ◽  
Conventional Concrete ◽  
Binding Material ◽  
Alumino Silicate ◽  
Alkaline Activator ◽  
Source Materials

Geopolymer concrete is an alternate to conventional concrete with reduced carbon emission, embodied energy and global warming potential and transforming waste product into an useful material. Geopolymer concrete is produced by mixing highly alkaline activator solution with alumino silicate source materials. Geopolymer concrete is highly viscous or sticky in nature, to overcome this drawback, an attempt has been made to study the effect of naphthalene based superplasticizer on geopolymer concrete blended with GGBS. Fly ash was replaced by GGBS at 20% increment levels, keeping a constant superplasticizer dosage at 3% by weight of binding material. Workability and strength characteristics were compared with those of geopolymer concrete blended with GGBS without superplasticizer. Up to certain replacement level of fly ash with GGBS, results in decrease of strength parameters with increase in workability, further replacement results in increase of strength with reduced workability with the addition of superplasticizer.

scholarly journals Practical Prediction Models of Tensile Strength and Reinforcement-Concrete Bond Strength of Low-Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 875
Author(s):  
Chenchen Luan ◽  
Qingyuan Wang ◽  
Fuhua Yang ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Bond Strength ◽  
Prediction Models ◽  
Splitting Tensile Strength ◽  
Geopolymer Concrete ◽  
Structural Factors ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Low Calcium

There have been a few attempts to develop prediction models of splitting tensile strength and reinforcement-concrete bond strength of FAGC (low-calcium fly ash geopolymer concrete), however, no model can be used as a design equation. Therefore, this paper aimed to provide practical prediction models. Using 115 test results for splitting tensile strength and 147 test results for bond strength from experiments and previous literature, considering the effect of size and shape on strength and structural factors on bond strength, this paper developed and verified updated prediction models and the 90% prediction intervals by regression analysis. The models can be used as design equations and applied for estimating the cracking behaviors and calculating the design anchorage length of reinforced FAGC beams. The strength models of PCC (Portland cement concrete) overestimate the splitting tensile strength and reinforcement-concrete bond strength of FAGC, so PCC’s models are not recommended as the design equations.

Experimental and Numerical Investigation of Critical Buckle Load of Composite Specimens

2015 ◽  
Vol 732 ◽  
pp. 85-90
Author(s):  
Lukáš Bek ◽  
Radek Kottner ◽  
Jan Krystek ◽  
Tomáš Kroupa
Keyword(s):  
Static Analysis ◽  
Glass Fibre ◽  
Large Deformations ◽  
Bending Test ◽  
Test Results ◽  
Beam Test ◽  
Three Point Bending ◽  
Box Beams ◽  
Buckle Beam ◽  
Thin Walled

Different carbon and glass fibre strips were subjected to the double clamp buckle beam test. Furthermore, thin-walled glass fibre box-beams were subjected to the three-point bending test. Results of experiments were compared to different numerical simulations using buckling analysis or static analysis considering large deformations.

Cryogenic Interlaminar Properties of PBO Fiber/Epoxy Composites

2011 ◽  
Vol 391-392 ◽  
pp. 1445-1449
Author(s):  
Chun Hua Zhang ◽  
Shi Lin Luan ◽  
Xiu Song Qian ◽  
Bao Hua Sun ◽  
Wen Sheng Zhang
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Liquid Nitrogen Temperature ◽  
Epoxy Composites ◽  
Bending Test ◽  
Test Results ◽  
Sem Images ◽  
Three Point Bending ◽  
Pbo Fiber ◽  
Interlaminar Shear

The influences of low temperature on the interlaminar properties for PBO fiber/epoxy composites have been studied at liquid nitrogen temperature (77 K) in terms of three point bending test. Results showed that the interlaminar shear strength at 77 K were significantly higher than those at room temperature (RT). For the analysis of the test results, the tensile behaviors of epoxy resin at both room temperature and liquid nitrogen temperature were investigated. The interface between fiber and matrix was observed using SEM images.

Alternative Concrete – Geopolymer Concrete

2021 ◽  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Construction Industry ◽  
Building Material ◽  
Construction Materials ◽  
Raw Material ◽  
Geopolymer Concrete ◽  
Sustainable Solutions ◽  
New Construction ◽  
Alkali Activated

Concrete is the most versatile, durable and reliable material and is the most used building material. It requires large amounts of Portland cement which has environmental problems associated with its production. Hence, an alternative concrete – geopolymer concrete is needed. The general aim of this book is to make significant contributions in understanding and deciphering the mechanisms of the realization of the alkali-activated fly ash-based geopolymer concrete and, at the same time, to present the main characteristics of the materials, components, as well as the influence that they have on the performance of the mechanical properties of the concrete. The book deals with in-depth research of the potential recovery of fly ash and using it as a raw material for the development of new construction materials, offering sustainable solutions to the construction industry.

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 Study of Proportional Variation of Geopolymer Concrete which Self Compacting Concrete

2019 ◽  
Vol 2 (2) ◽  
pp. 65
Author(s):  
Purwanto P. ◽  
Himawan Indarto
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plant ◽  
Portland Cement ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Conventional Concrete ◽  
Basic Characteristics ◽  
Carbon Dioxide Co2 ◽  
Proportional Variation

Portland cement production process which is the conventional concrete constituent materials always has an impact on producing carbon dioxide (CO2) which will damage the environment. To maintain the continuity of development, while maintaining the environment, Portland cement substitution can be made with more environmentally friendly materials, namely fly ash. The substitution of fly ash material in concrete is known as geopolymer concrete. Fly ash is one of the industrial waste materials that can be used as geopolymer material. Fly ash is mineral residue in fine grains produced from coal combustion which is mashed at power plant power plant [15]. Many cement factories have used fly ash as mixture in cement, namely Portland Pozzolan Cement. Because fly ash contains SiO2, Al2O3, P2O3, and Fe2O3 which are quite high, so fly ash is considered capable of replacing cement completely.This study aims to obtain geopolymer concrete which has the best workability so that it is easy to work on (Workable Geopolymer Concrete / Self Compacting Geopolymer Concrete) and obtain the basic characteristics of geopolymer concrete material in the form of good workability and compressive strength. In this study, geopolymer concrete is composed of coarse aggregate, fine aggregate, fly ash type F, and activators in the form of NaOH and Na2SiO3 Be52. In making geopolymer concrete, additional ingredients such as superplastizer are added to increase the workability of geopolymer concrete. From this research, the results of concrete compressive strength above fc' 25 MPa and horizontal slump values reached 60 to 80 centimeters.

Complementary Use of Inductive Test and Bending Test for the Characterization of SFRC

2014 ◽  
Vol 580-583 ◽  
pp. 2213-2219 ◽  
Author(s):  
Lin Liao ◽  
Sergio Cavalaro ◽  
Albert de la Fuente ◽  
Antonio Aguado
Keyword(s):  
Steel Fibre ◽  
Fibre Orientation ◽  
Bending Test ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Flexural Behaviour ◽  
Steel Fibre Reinforced Concrete ◽  
Three Point Bending ◽  
Experimental Campaign

Many researches have been conducted in past decades for promoting the application of steel fibre reinforced concrete (SFRC), either conventional or self-compacting. However, the differences of post-crack behaviour and the properties of these two types of concrete remains unclear. The objective of this paper is to analyse such differences in terms of flexural behaviour, fibre orientation and contribution as well as the fibre content. For that, an extensive experimental campaign was carried out. In total 3 mixes of self-compacting and 3 mixes with traditional concrete were produced with the nominal fibre contents of 30kg/m3, 45kg/m3 and 60kg/m3. In each series, specimens were produces and characterized by three point bending test (code EN 14651) and inductive test. The results illustrate how fibre orientation and distribution justify the differences in the mechanical behaviour of the materials and the scatter of the bending test results.

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