scholarly journals Workability and Flexural Properties of Fibre-Reinforced Geopolymer Using Different Mono and Hybrid Fibres

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4447
Author(s):  
Jacob Junior ◽  
Ashish Kumer Saha ◽  
Prabir Kumar Sarker ◽  
Alokesh Pramanik
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Single Type ◽  
Flexural Properties ◽  
Multiple Cracking ◽  
Binder Ratio ◽  
Low Modulus ◽  
Mixed Types ◽  
Hybrid Forms

The effects of mono (single type) and hybrid (mixed types) fibres on the workability, compressive strength, flexural strength, and toughness parameters of fly ash geopolymer mortar were studied. The ratio of sand to geopolymer paste of the mortar was 2.75. It was found that workability of mortar decreased more with the use of PP fibres due to its higher dispersion into individual filaments in geopolymer mortar compared to the bundled ARG and PVA fibres. Compressive strength increased by 14% for using 1% steel with 0.5% PP fibres compared to that of the control mixture, which was 48 MPa. However, 25 to 30% decrease of compressive strength was observed in the mortars using the low-modulus fibres. Generally, flexural strength followed the trend of compressive strength. Deflection hardening behaviours in terms of the ASTM C1609 toughness indices, namely I5, I10 and I20 were exhibited by the mortars using 1% steel mono fibres, 0.5% ARG with 0.5% steel and 1% PVA with 0.5% steel hybrid fibres. The toughness indices and residual strength factors of the mortars using the other mono or hybrid fibres at 1 or 1.5% dosage were relatively low. Therefore, multiple cracking and deflection hardening behaviours could be achieved in fly ash geopolymer mortars of high sand to binder ratio by using steel fibres in mono or hybrid forms with ARG and PVA fibres.

Effects of Fly Ash/Slag Ratio and Liquid/Binder Ratio on Strength of Alkali-Activated Fly Ash/Slag Mortars

2013 ◽  
Vol 377 ◽  
pp. 50-54 ◽  
Author(s):  
Mao Chieh Chi ◽  
Yen Chun Liu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
The Other ◽  
Factors Influencing ◽  
Binder Ratio ◽  
Alkali Activated ◽  
Significant Factors

The purpose of this study is to investigate the effects of fly ash/slag ratio and liquid/binder ratio on strength of alkali-activated fly ash/slag (AAFS) mortars. Three liquid/binder ratios of 0.35, 0.5 and 0.65 and three fly ash/slag ratios of 100/0, 50/50, and 0/100 were selected as variables to design and produce mixes of AAFS mortars. The compressive strength and flexural strength of alkali-activated fly ash/slag mortars were discussed and compared with reference mortars produced using ordinary Portland cement (OPC) mortars. Based on the results, both fly ash/slag ratio and the liquid/binder ratio are significant factors influencing the strengths of AAFS mortars. The strength of AAFS mortars except alkali-activated fly ash mortars is higher than that of OPC mortars. When the fly ash/slag ratio reaches 50/50, the AAFS mortars possesses the highest strength compared with the other mortars.

scholarly journals Evaluation of Hybrid Melamine and Steel Fiber Reinforced Geopolymers Composites

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5548
Author(s):  
Patrycja Bazan ◽  
Barbara Kozub ◽  
Michał Łach ◽  
Kinga Korniejenko
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Hybrid System ◽  
Steel Fiber ◽  
Base Material ◽  
Steel Fibers ◽  
Polymer Fibers ◽  
Single Type ◽  
Geopolymer Composites

This study investigated the influence of the steel and melamine fibers hybridization on the flexural and compressive strength of a fly ash-based geopolymer. The applied reinforcement reduced the geopolymer brittleness. Currently, there are several types of polymer fibers available on the market. However, the authors did not come across information on the use of melamine fibers in geopolymer composites. Two systems of reinforcement for the composites were investigated in this work. Reinforcement with a single type of fiber and a hybrid system, i.e., two types of fibers. Both systems strengthened the base material. The research results showed the addition of melamine fibers as well as steel fibers increased the compressive and flexural strength in comparison to the plain matrix. In the case of a hybrid system, the achieved results showed a synergistic effect of the introduced fibers, which provided better strength results in relation to composites reinforced with a single type of fiber in the same amount by weight.

scholarly journals Assessment of the Rheological and Mechanical Properties of Geopolymer Concrete Comprising Fly Ash and Fluid Catalytic Cracking Residue as Aluminosilicate Precursor

2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Catalytic Cracking ◽  
Fluid Catalytic Cracking ◽  
High Alumina ◽  
Geopolymer Concrete ◽  
Sem Images

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.

scholarly journals Strength Time–Varying and Freeze–Thaw Durability of Sustainable Pervious Concrete Pavement Material Containing Waste Fly Ash

2018 ◽  
Vol 11 (1) ◽  
pp. 176 ◽  
Author(s):  
Hanbing Liu ◽  
Guobao Luo ◽  
Longhui Wang ◽  
Yafeng Gong
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Pervious Concrete ◽  
Early Age ◽  
Pavement Materials ◽  
Freeze Thaw ◽  
Replacement Method ◽  
Porosity And Permeability ◽  
Volume Method

Pervious concretes, as sustainable pavement materials, have great advantages in addressing a number of environmental issues. Fly ash, as the industrial by-product waste, is the most commonly used as cement substitute in concrete. The objective of this paper is to study the effects of waste fly ash on properties of pervious concrete. Fly ash was used to replace cement with equivalent volume method at different levels (3%, 6%, 9%, and 12%). The control pervious concrete and fly ash modified pervious concrete were prepared in the laboratory. The porosity, permeability, compressive strength, flexural strength, and freeze–thaw resistance of all mixtures were tested. The results indicated that the addition of fly ash decreased the early-age (28 d) compressive strength and flexural strength, but the long-term (150 d) compressive strength and flexural strength of fly ash modified pervious concrete were higher than that of the early-age. The adverse effect of fly ash on freeze–thaw resistance of pervious concrete was observed when the fly ash was added. The porosity and permeability of all pervious concrete mixtures changed little with the content of fly ash due to the use of equal volume replacement method. Although fly ash is not positive to the properties of pervious concrete, it is still feasible to apply fly ash as a substitute for cement in pervious concrete.

scholarly journals Kajian Karakteristik Beton Memadat Sendiri yang Menggunakan Serat Ijuk (Hal. 54-65)

2018 ◽  
Vol 4 (4) ◽  
pp. 54
Author(s):  
Iis Nurjamilah ◽  
Abinhot Sihotang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
High Strength ◽  
Self Compacting Concrete ◽  
Palm Fiber ◽  
Fiber Concrete ◽  
Dilute Mixture

ABSTRAKKajian karakteristik beton memadat sendiri yang menggunakan serat ijuk merupakan sebuah kajian yang dilakukan untuk mengetahui pengaruh penambahan serat ijuk terhadap karakteristik beton memadat sendiri (SCC). Beton memadat sendiri yang menggunakan serat ijuk (PFSCC) didesain memiliki campuran yang encer, bermutu tinggi (= 40 MPa) dan memiliki persentase kekuatan lentur yang lebih baik. PFSCC  didapatkan dari hasil pencampuran antara semen sebanyak 85%, fly ash 15%, superplastizicer 1,5%, serat ijuk 0%, 0,5%; 1%; 1,5%; 2% dan 3% dari berat binder (semen + fly ash), kadar air 190 kg/m3, agregat kasar 552,47 kg/m3 dan pasir 1.063 kg/m3. Semakin banyak persentase penambahan serat ijuk ke dalam campuran berdampak terhadap menurunnya workability beton segar. Penambahan serat ijuk yang paling baik adalah sebanyak 1%, penambahan tersebut dapat meningkatkan kekuatan tekan beton sebesar 13% dan lentur sebesar 1,8%.Kata kunci: beton memadat sendiri (SCC), beton berserat, beton memadat sendiri yang menggunakan serat ijuk (PFSCC), serat ijuk ABSTRACTThe study of characteristics self compacting concrete using palm fibers is a study conducted to determine the effect of adding palm fibers to characteristics of self compacting concrete (SCC). palm fibers self compacting concrete (PFSCC) is designed to have a dilute mixture, high strength (= 40 MPa), and have better precentage flexural strength. PFSCC was obtained from mixing of 85% cement, 15% fly ash, 1.5% superplastizicer, 0%, 0.5%, 1%, 1.5%, 2% and 3% palm fibers from the weight of binder  (cement + fly ash), water content 190 kg/m3, coarse aggregate 552.47 kg/m3 and sand 1,063 kg/m3. The more persentage palm fibers content added to the mixture makes workability of fresh concrete decreases. The best addition of palm fiber is 1%, this addition can increases the compressive strength 13% and flexural strength 1.8%.Keywords: self compacting concrete (SCC), fiber concrete, Palm fiber self compacting concrete (PFSCC), palm fiber

Research in the Preparation of Paving Bricks with Construction Garbage

2013 ◽  
Vol 712-715 ◽  
pp. 917-920
Author(s):  
Lian Xi Wang ◽  
Guang Hui Pan ◽  
Fu Yong Li ◽  
Hai Ming Wang ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Experimental Results ◽  
Replacement Rate ◽  
Coarse Aggregates ◽  
Waste Concrete ◽  
Fine Aggregates ◽  
Binder Ratio ◽  
Water Binder Ratio

Construction garbage paving bricks were made of recycled coarse and fine aggregates which were prepared by the waste concrete. The influence of replacement rate of recycled coarse aggregates, water-binder ratio and excitation agent dosage on the compressive strength and flexural strength of construction garbage paving bricks were researched. The experimental results show that optimum replacement rate of recycled coarse aggregates, water-binder ratio and excitation agent dosage were 100%, 0.43 and 1.5% respectively. In this proportion, the 7d, 28d compressive strength of the products were 15.6MPa, 37.5MPa respectively, and the 7d, 28d flexural strength were 2.0MPa, 4.3MPa respectively, which fit the requirements of the Cc30 level of compressive strength and the Cf4.0 level of flexural strength involved in JCT 446-2000 "concrete pavers".

scholarly journals Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

2019 ◽  
Vol 9 (2) ◽  
pp. 4701-4704
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Mechanical Characteristics ◽  
Coarse Aggregate ◽  
High Strength ◽  
Set Up

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

Study on Production of Autoclaved Aerated Concrete by Coal Gangue Fly Ash

2013 ◽  
Vol 357-360 ◽  
pp. 949-954
Author(s):  
Ye Zhang ◽  
Peng Xuan Duan ◽  
Bao Sheng Jia ◽  
Lei Li
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Drying Shrinkage ◽  
Coal Gangue ◽  
National Standards ◽  
Raw Material ◽  
Autoclaved Aerated Concrete ◽  
Binder Ratio ◽  
Material Formulation ◽  
Aerated Concrete

In this paper, the low-silicon coal gangue fly ash is used to produce autoclaved aerated concrete. The influences of water binder ratio, coal gangue fly ash content, calcareous content and conditioning agents on the compressive strength of the autoclaved aerated concrete are investigated. Optimal raw material formulation and procedure are determined for the autoclaved aerated concrete. The compressive strength and frost resistance of autoclaved aerated concrete made by the optimal raw material formulation and procedure meet with the requirements of autoclaved aerated concretes of B05 grade, and its thermal conductivity, drying shrinkage reach the requirements of the relevant national standards of China.

scholarly journals Effects of the Amount of Fly Ash Modified by Stearic Acid Compound on Mechanical Properties, Flame Retardant Ability, and Structure of the Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Tuan Anh Nguyen
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Stearic Acid ◽  
Flame Retardant ◽  
Burning Rate ◽  
Thermal Power ◽  
Waste Product ◽  
Fire Retardant

Fly ash, a waste product from thermal power plants, is one of the good alternatives for use as a filler in polymers, especially in flame retardants. Fly ash is an environmentally friendly fire retardant additive for composites, used in place of conventional flame retardant additives such as halogenated organic compounds, thus promoting environmental safety. In this study, fly ash was modified with stearic acid to improve adhesion at the polymers interface and increase compatibility. Fly ash was studied at various volumes (5, 10, and 20 wt.% fly ash) used in this study to synthesize fly ash-epoxy composites. The results show that the tensile strength, flexural strength, compressive strength, and impact strength of these synthetic materials increase when fly ash is modified to the surface, compressive strength: 197.87 MPa, flexural strength: 75.20 MPa, impact resistance: 5.77 KJ/m2, and tensile strength: 47.89 MPa. Especially, the fire retardant properties are improved at a high level, with a modified 20% fly ash content: the burning rate of 16.78 mm/min, minimum oxygen index of 23.2%, and meet the fire protection standard according to UL 94HB with a burning rate of 8.09 mm/min. Scanning electron microscopy (SEM) and infrared spectroscopy were used to analyze the morphological structure of fly ash after being modified and chemically bonded with epoxy resin background.

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