Compressive Strength and Thermal Conductivity of Fly Ash Geopolymer Concrete Incorporated with Lightweight Aggregate, Expanded Clay Aggregate and Foaming Agent

This paper investigates the effect of incorporation of lightweight aggregate and foam in the preparation of lightweight aggregate geopolymer concrete (LWAGC) and lightweight aggregate foamed geopolymer concrete (LWAFGC). The geopolymer paste was formed by alkali activation of Class F fly ash in mixture of sodium silicate and sodium hydroxide solution. LWAGC was incorporated with expanded clay lightweight aggregate and river sand while hydrogen peroxide was added as foaming agent for LWAFGC. Results showed that LWAGC and LWAFGC achieved an excellent 28-day compressive strength of 60 MPa and 20 MPa, respectively. The bulk densities were 1815 kg/m3 for LWAGC and 1593 kg/m3 for LWAFGC. Even so, low thermal conductivity of 0.12 W/mK and 0.09 W/mK were reported. It was concluded that the joint effect of lightweight aggregate and foam produced geopolymer concrete with good mechanical strength while having excellent thermal insulating properties. The geopolymer concretes possessed high strength-to-density ratio to be regarded as lightweight high-performance structures.

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Compressive Strength and Thermal Conductivity of Fly Ash Geopolymer Concrete Incorporated with Lightweight Aggregate, Expanded Clay Aggregate and Foaming Agent

Revista de Chimie ◽

10.37358/rc.70.19.11.7695 ◽

2019 ◽

Vol 70 (11) ◽

pp. 4021-4028

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Fly Ash ◽

Lightweight Concrete ◽

Sodium Hydroxide Solution ◽

Density Ratio ◽

Lightweight Aggregate ◽

Alkali Activation ◽

Geopolymer Concrete ◽

Foaming Agent

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Production of lightweight Geopolymer concrete using artificial local lightweight aggregate

MATEC Web of Conferences ◽

10.1051/matecconf/201816202024 ◽

2018 ◽

Vol 162 ◽

pp. 02024

Author(s):

Waleed Abbas ◽

Wasan Khalil ◽

Ibtesam Nasser

Keyword(s):

Thermal Conductivity ◽

Tensile Strength ◽

Compressive Strength ◽

Flexural Strength ◽

Lightweight Concrete ◽

Lightweight Aggregate ◽

Experimental Tests ◽

Pulse Velocity ◽

Dry Density ◽

Geopolymer Concrete

Due to the rapid depletion of natural resources, the use of waste materials and by-products from different industries of building construction has been gaining increased attention. Geopolymer concrete based on Pozzolana is a new material that does not need the presence of Portland cement as a binder. The main focus of this research is to produce lightweight geopolymer concrete (LWGPC) using artificial coarse lightweight aggregate which produced from locally available bentonite clays. In this investigation, the binder is low calcium fly ash (FA) and the alkali activator is sodium hydroxide and sodium silicate in different molarities. The experimental tests including workability, fresh density, also, the compressive strength, splitting tensile strength, flexural strength, water absorption and ultrasonic pulse velocity at the age of 7, 28 and 56 days were studied. The oven dry density and thermal conductivity at 28 days age are investigated. The results show that it is possible to produce high strength lightweight geopolymer concrete successfully used as insulated structural lightweight concrete. The 28-day compressive strength, tensile strength, flexural strength, dry density, and thermal conductivity of the produced LWGPC are 35.8 MPa, 2.6MPa, 5.5 MPa, 1835kg/m3, and 0.9567 W/ (m. K), respectively.

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Fly Ash Based Lightweight Geopolymer Concrete Using Foaming Agent Technology

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.679.20 ◽

2014 ◽

Vol 679 ◽

pp. 20-24 ◽

Cited By ~ 7

Author(s):

Mohd Mustafa Al Bakri Abdullah ◽

Zarina Yahya ◽

Muhammad Faheem Mohd Tahir ◽

Kamarudin Hussin ◽

Mohammed Binhussain ◽

...

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Room Temperature ◽

Lightweight Concrete ◽

Agent Technology ◽

Alkali Activation ◽

Geopolymer Concrete ◽

Foaming Agent ◽

Curing Conditions ◽

Foam Generator

This paper presents the mechanical properties of a lightweight geopolymer concrete synthesized by the alkali-activation of a fly ash source (FA) produced by mixing a paste of geopolymer with foam produced by using NCT Foam Generator. Two curing conditions are used, curing at room temperature and curing in an oven with a constant temperature which is 60 oC. Bulk density showed that fly ash-based geopolymer lightweight concrete is light with the density of 1225 kg/m3 - 1667 kg/m3 with an acceptable compressive strength of 17.60 MPa for the density of 1667 kg/m3.

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Empirical Investigation on Compressive Strength of Geopolymer and Conventional Concretes by Nondestructive Method

Advances in Materials Science and Engineering ◽

10.1155/2021/9575964 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

B. Ravali ◽

K. Bala Gopi Krishna ◽

D. Ravi Kanth ◽

K. J. Brahma Chari ◽

S. Venkatesa Prabhu ◽

...

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Ultrasonic Pulse Velocity ◽

Ultrasonic Pulse ◽

Pulse Velocity ◽

Nondestructive Method ◽

Geopolymer Concrete ◽

River Sand ◽

Rebound Hammer ◽

Compressive Strength Of Concrete

Need of construction is increasing due to increase in population growth rate. The geopolymer concrete is eco-friendly than ordinary concrete. Current experimental investigation was conducted on ordinary and geopolymer concrete using nondestructive testing (NDT) tests like ultrasonic pulse velocity (UPV) test and rebound hammer (RH) test. Cube specimens of dimensions 150 mm × 150 mm × 150 mm are used to conduct these tests at 7, 14, and 28 days. Proportions considered for concrete are cement-fly ash-river sand (100-0-100% and 60-40-100%), cement-fly ash-robo sand (100-0-100% and 60-40-100%) whereas geopolymer concrete fly ash-metakaolin is taken in proportions of 100-0%, 60-40%, and 50-50%. Alkaline activators (sodium hydroxide and sodium silicate with molarity 12M) were used in preparing geopolymer concrete. The major objective of the current study is to obtain relation between compressive strength of concrete and UPV values.

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A study on the strength development of geopolymer concrete using fly ash

International Journal of Engineering & Technology ◽

10.14419/ijet.v6i4.7761 ◽

2017 ◽

Vol 6 (4) ◽

pp. 163 ◽

Cited By ~ 2

Author(s):

Ramesh Babu Chokkalingam ◽

Ganesan N

Keyword(s):

Fly Ash ◽

Sodium Hydroxide ◽

Sodium Silicate ◽

Sodium Hydroxide Solution ◽

Fine Sand ◽

Strength Development ◽

Alkali Activation ◽

Geopolymer Concrete ◽

Water Contaminants ◽

Significant Difference

Cement consumption is increasing day by day due to the tremendous development in the infrastructure facilities. The production of one ton of cement emits approximately one ton of carbon dioxide to the atmosphere. In order to reduce the use of cement a new-generation concrete has been developed such as geopolymer concrete (GPC).Geopolymer Geopolymer is a new material which has the potential to replace ordinary Portland cement. It is an inorganic material synthesized by alkali activation of amorphous aluminosilicates at ambient or slightly increased temperatures having an amorphous to semi-crystalline polymeric structure. In this study, low calcium flyash from Tuticorin was used to produce geopolymer concrete. The geopolymer was synthesized with sodium silicate and sodium hydroxide solutions. The sodium hydroxide pellets was dissolved in the distilled water to make free from mixing water contaminants. The ratio of sodium silicate and sodium hydroxide ratio was kept as 2.5. The concentration of sodium hydroxide solution is 12 Molarity (12M). Other materials used are locally available coarse aggregate and fine sand in surface dry condition. A polycarboxlate HRWRA La Hypercrete S25was used. Cubes of size 100mm were cast for six mix proportions of 450kg/m3 flyash+0.35W/B, 500 kg/m3 flyash+0.35W/B, 550kg/m3 flyash+0.35W/B, 450kg/m3 flyash+.0.40 W/B, 500kg/m3 fly ash+0.40W/B and 550kg/m3 flyash+0.40W/B. The specimens after casting in moulds were kept in oven at 60°C for 6 hours and left to air dry at room temperature and tested at 7 and 28 days. The test results revealed the compressive strength of 30 Mpa was achieved. There was not much significant difference in strength development at 28 days between the mixes due to the increase of flyash content. The microstructural images at 28 days revealed that there was not much difference in the microstructure due to the variation in flyash content from 450 kg/m3 to 550 kg/m3.

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Alkali-Activated Fly Ash Foams – Synthesis, Chemo-Physical Properties and Microstructure Modeling

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.92.14 ◽

2014 ◽

Vol 92 ◽

pp. 14-19 ◽

Cited By ~ 1

Author(s):

Petr Hlaváček ◽

Vit Šmilauer ◽

František Škvára

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Fly Ash ◽

Thermal Capacity ◽

Alkali Activation ◽

Activation Process ◽

Strain Diagram ◽

Element Analysis ◽

Aluminium Powder ◽

One Year

Inorganic foams offer several unique properties such as low thermal conductivity, fire resistance, or UV stability. Inorganic foam specimens were synthesized from fly ash and aluminium powder through an alkali-activation process. Depending on mix proportions, bulk densities ranged between 400 and 800 kg/m3. Thermal treatment at 80°C for 12 hours accelerated curing process. Compressive strength was found in the range 4.5-9.0 MPa, flexural strength 0.6-1.7 MPa, Young's modulus 0.6-1.1 GPa, thermal conductivity 0.14-0.16 W/m/K and thermal capacity around 1100 J/kg/K. Exposing the foams to temperature 800°C led to a small decrease of compressive strength while exposure to 1100°C sintered the foam to higher strength of 13 MPa. Volumetric shrinkage 20% occurred at 1100°C without further disintegration. Residual compressive strength was determined after exposure to NaCl, HCl, Na2SO4, MgSO4, H2SO4. The highest reduction to 20% occured in both acids with pH=2 after one year of exposition. Digitized microstructures entered finite element analysis to validate a stress-strain diagram.

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Compressive Strength of Fly ash-based Geopolymer Concrete with a Variable of Sodium Hydroxide (NaOH) Solution Molarity

MATEC Web of Conferences ◽

10.1051/matecconf/201814701004 ◽

2018 ◽

Vol 147 ◽

pp. 01004 ◽

Cited By ~ 3

Author(s):

Herwani ◽

Ivindra Pane ◽

Iswandi Imran ◽

Bambang Budiono

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Sodium Hydroxide ◽

Raw Materials ◽

Sodium Hydroxide Solution ◽

Solution Concentration ◽

Geopolymer Concrete ◽

Hydroxide Solution ◽

Naoh Solution ◽

New Material

Geopolymer concrete is a new material made by activating the raw materials which contain many elements of silica and alumina. Compressive strength of geopolymer concrete produced was influenced by the concentration of the activator solution. This paper presents an experimental investigation into fly ash-based geopolymer concrete. Research objective was to investigate the effects of alkaline activator solution (AAS) molarity on compressive strength of geopolymer concrete. Variable of the test were a solution to sodium hydroxide was chosen as the activator solution. Concentration of sodium hydroxide solution used was 10 M, 12 M and 14 M with ambient curing. The specimen is made of concrete cylinder with diameter 10 cm and height 20 cm as many as 9 pieces each variable. Compressive strength tests is performed when the concrete is 7, 14, and 28 days old. Results of the test are indicated that the increasing of sodium hydroxide (NaOH) solution concentration leads to improve the compressive strength of geopolymer concrete. The optimal compressive strength of geopolymer concrete was achieved at a concentration of sodium hydroxide solution (NaOH) of 12 M. Geopolymer concretes compressive strength only achieves around 50-60% of the planned.

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Use of Recycled Concrete Aggregate in High-Calcium Fly Ash Geopolymer Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.718.163 ◽

2016 ◽

Vol 718 ◽

pp. 163-168 ◽

Cited By ~ 2

Author(s):

Tawatchai Tho-In ◽

Vanchai Sata ◽

Trinh Cao ◽

Prinya Chindaprasirt

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Fly Ash ◽

Pulse Velocity ◽

Recycled Concrete ◽

Concrete Aggregate ◽

Geopolymer Concrete ◽

Comparison Results ◽

High Calcium ◽

High Calcium Fly Ash

The comparison results of using crushed limestone (NA) and recycled concrete aggregates (RCA) as coarse aggregates in high-calcium fly ash geopolymer concrete with and without temperature curing are presented. Local river sand with a fineness modulus of 2.1, sodium hydroxide solution concentrations of 8, 12, and 16 Molar, and sodium silicate were used to produce geopolymer concrete (GC). The curing was separated in two conditions: the first was cured at ambient temperature (AT) and another was cured at temperature of 60°C for 48 hrs. (CT). The compressive strength, thermal conductivity, and ultra pulse velocity of GC were investigated at age 7 days. The results found that RCA could be use as coarse aggregate in GC. The thermal conductivity increased with the increasing of compressive strength. Curing at 60°C yielded compressive strength about 3 times higher than that of AT. However, both AT and CT curing, GC containing RCA had thermal conductivity and ultra pulse velocity lower than those of containing NA.

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The Effects of Water to Solid Ratio, Activator to Binder Ratio, and Lime Proportion on the Compressive Strength of Ambient-Cured Geopolymer Concrete

Journal of the Civil Engineering Forum ◽

10.22146/jcef.43878 ◽

2019 ◽

Vol 5 (2) ◽

pp. 161 ◽

Cited By ~ 1

Author(s):

Andi Arham Adam

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Sodium Hydroxide Solution ◽

Geopolymer Concrete ◽

Solid Ratio ◽

Slaked Lime ◽

Binder Ratio ◽

Class F Fly Ash ◽

Good Workability ◽

Class F

Low calcium fly ash based Geopolymer has been proven to be one of the potential alternatives substitutes to Portland Cement not only due to its high resistance to chemical attack but also because of the vast availability of class F fly ash for raw materials. However, one of the limitations of geopolymer as the alternative binders in concrete is that the strength develops slowly under ambient condition. This paper presented the investigation of water to solid ratio, activator to binder ratio, and lime proportion on the compressive strength of ambient-cured geopolymer concrete. To develop sufficient strength at an early age, class F fly ash and slaked lime (Ca (OH)2) were used as the binder with the proportion of lime to binder of 4%, 5%, 6%, and 7%. The blended binder was activated by sodium silicate and sodium hydroxide solution with the variation of activator to binder ratio of 0.45, 0.5, 0.55, and 0.6. The water to solid ratio of 0.30, 0.31, 0.32, and 0.33 was chosen to facilitate good workability which was done by adding water to the mix. The compressive strength tests were conducted at 7, 14, and 28 days on the cylindrical concrete specimens with a dimension of 100 mm diameter and 200 mm height. The results show that the activator to binder ratio of 0.50 to 0.55, and the proportion of lime to the binder of 6% to 7% were the optimum range value. It was also found that the lower the water to cement ratio the higher the compressive strength and the water to solid ratio as low as 0.3 produced the highest compressive strength while still maintaining good workability.

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Effect of Chemical Composition of Different Source Materials on 28th Day Compressive Strength of Geopolymer Concrete Cured Under Ambient Conditions

10.29007/dmcv ◽

2018 ◽

Author(s):

Aanal Shah ◽

C.B. Shah

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Sodium Hydroxide Solution ◽

Curing Temperature ◽

Partial Replacement ◽

Chemical Components ◽

Geopolymer Concrete ◽

Ambient Conditions ◽

Complete Replacement ◽

Granulated Blast Furnace Slag

There have been increasing efforts in recent years to minimize the amount of cement used in concrete. Efforts at partial replacement have been successful and regulations are promulgated to standardize and use such successful formulations. There is now worldwide research aimed at complete replacement of cement by activating industrial materials that are rich in silica and alumina with alkaline solution. The present study aims at complete elimination of cement through the development of a geopolymer concrete containing fly ash and ground granulated blast furnace slag (GGBS), activated by sodium based alkaline activators. The effect of replacing up to 50% fly ash by GGBS is also studied. The strength parameters are measured for a mixture of sodium silicate and sodium hydroxide solution having concentrations from 2M to 12M. The samples are cured under ambient conditions. Compressive and split tensile strengths of cubes and cylinders for all mixtures were measured on the 28th day of casting. The overall data pertaining to compressive strength and chemical components along with curing temperature is compiled to achieve generalized predictable results. Comparative charts were developed in terms of temperature, quantity of NaOH and SiO2/CaO for compressive strength.

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