Effect of NaOH concentration and fly ash/alkaline activator ratio on the compressive strength of road base material

This paper reports the results of an experimental work conducted to investigate the effect of curing conditions on the properties of fly ash-based geopolymer bricks prepared by using fly ash as base material and combination of sodium hydroxide and sodium silicate as alkaline activator. The experiments were conducted by varying the curing time in the range of 1-24 hours respectively. The specimens cured for a period of 24 hours have presented the highest compressive strength for all ratio of fly ash to sand. For increasing curing time improve compressive strength and decreasing water absorption.

Download Full-text

Research on the Mechanical Performance of the Road Base Materials with Steel Slag Sand

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.174-177.676 ◽

2012 ◽

Vol 174-177 ◽

pp. 676-680

Author(s):

Fang Xu ◽

Ming Kai Zhou ◽

Jian Ping Chen

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Unconfined Compressive Strength ◽

Mechanical Performance ◽

Steel Slag ◽

Base Material ◽

Strength Performance ◽

The Road ◽

Road Base ◽

Base Materials

The unconfined compressive strength is used to be the valuation index, the mechanical performance of three kinds of new road base material, which are fly ash stabilized steel slag sand (FA-SS for short), lime and fly ash stabilized steel slag sand (L-FA-SS for short), cement and fly ash stabilized steel slag sand(C-FA-SS for short), are studied in this paper. The results show that the unconfined compressive strength performance of FA-SS is similar to L-FA-SS, and it can meet the highest strength when the ratio of steel slag to fly ash is 1:1~2:1. When the ratio of fly ash to the steel slag is 10:90, it is good to use cement stabilizing. Comparing the new road base materials with the traditional road base material, the former has better strength performance and economy function advantage.

Download Full-text

Modification of Lime-Fly Ash-Crushed Stone with Phosphogypsum for Road Base

Advances in Civil Engineering ◽

10.1155/2020/8820522 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

Hao Zhang ◽

Yuan Cheng ◽

Lei Yang ◽

Weikang Song

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Base Material ◽

Engineering Properties ◽

Crushed Stone ◽

Fine Aggregate ◽

The Road ◽

Road Base ◽

Shrinkage Cracks ◽

Phosphogypsum Waste

In order to increase the recycling of phosphogypsum waste, this study explored the feasibility of using phosphogypsum to replace some of the lime and aggregate in the lime-fly ash-crushed stone mixture which is a widely used road base material in China. For this purpose, compaction, compressive strength, composition structures, wetting-drying cycle tests, and shrinkage tests were carried out on the lime-fly ash-phosphogypsum-crushed stone composite to investigate its performance. The results indicate that lime-fly ash-crushed stone modified with phosphogypsum has the required strength of the road base material and favourable performances in environment (wetting-drying cycle) stability. The image processing analysis and shrinkage tests demonstrated that phosphogypsum can significantly improve the compactness and shrinkage performance of lime-fly ash-crushed stone mixture. A suitable content of phosphogypsum and a reasonable content of fine aggregate are conducive to improving the roadway engineering properties (i.e., decreasing shrinkage cracks and increasing compressive strength) of lime-fly ash-phosphogypsum-crushed stone composites.

Download Full-text

The Effect of Alkaline Activator Ratio on the Compressive Strength of Fly Ash-Based Geopolymer Paste

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/209/1/012064 ◽

2017 ◽

Vol 209 ◽

pp. 012064 ◽

Cited By ~ 7

Author(s):

A V Lăzărescu ◽

H Szilagyi ◽

C Baeră ◽

A Ioani

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Alkaline Activator ◽

Geopolymer Paste

Download Full-text

Alkali-activated concretes based on fly ash and blast furnace slag: Compressive strength, water absorption and chloride permeability

Ingeniería e Investigación ◽

10.15446/ing.investig.v40n2.83893 ◽

2020 ◽

Vol 40 (2) ◽

Author(s):

Daniela Eugenia Angulo-Ramírez ◽

William Gustavo Valencia-Saavedra ◽

Ruby Mejía de Gutiérrez

Keyword(s):

Compressive Strength ◽

Blast Furnace ◽

Fly Ash ◽

Water Absorption ◽

Blast Furnace Slag ◽

Construction Materials ◽

Chloride Ion ◽

Chloride Permeability ◽

Alkaline Activator ◽

Furnace Slag

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.

Download Full-text

Effect of Curing Time and Sintering to the Properties of Geopolymer Mortars

Materials Science Forum ◽

10.4028/www.scientific.net/msf.888.184 ◽

2017 ◽

Vol 888 ◽

pp. 184-187

Author(s):

Salwa Ismail ◽

Mohammad Faizal Mohd Razali ◽

Izwan Johari ◽

Zainal Arifin Ahmad ◽

Shah Rizal Kasim

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Distilled Water ◽

Curing Time ◽

Pore Former ◽

X Ray ◽

Before And After ◽

Naoh Solution ◽

Added Water ◽

Alkaline Activator

In this study, the geopolymer mortars were synthesized with fly ash (FA) and silica powder as aluminosilicate sources and a combination of sodium hydroxide (NaOH) solution, sodium silicate (Na2SiO3) solution and distilled water as alkaline activator. Commercial sago was used as a pore former in the mortars. The percentage of sago used were 10, 20 and 30 wt% of FA. The amount of added water used in each mixture was 5% by weight of FA, NaOH solution and Na2SiO3 solution. The formed geopolymer mortars were cured for 1, 3 and 7 days and sintered at 1000 °C. X-ray fluoresence (XRF) shown that FA contains higher amount of silica (SiO2) and alumina (Al2O3) which is important as aluminosilicate sources. The properties of the geopolymer mortars before and after sintered at 1000 °C have been investigated. The results show that geopolymer mortars with 10% of sago content with curing time of 7 days and sintered at 1000 °C give the highest compressive strength of 13.5 MPa.

Download Full-text

Effect of Partial Replacement of Fly Ash by Metakaolin on Strength Development of Fly Ash Based Geopolymer Mortar

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.744.131 ◽

2017 ◽

Vol 744 ◽

pp. 131-135 ◽

Cited By ~ 4

Author(s):

Muhammad Zahid ◽

Nasir Shafiq ◽

Mohd Fadhil Nuruddin ◽

Ehsan Nikbakht ◽

Asif Jalal

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Sodium Hydroxide Solution ◽

Base Material ◽

Sodium Silicate Solution ◽

Silicate Solution ◽

Partial Replacement ◽

Strength Development ◽

Class C ◽

Class F

This article aims to investigate the compressive strength variation by the addition of metakaolin as a substitute of fly ash in the fly ash based geopolymer mortar. Five, ten and fifteen percent by weight of fly ash was replaced by highly reactive metakaolin. Two type of fly ashes namely, ASTM class F and ASTM class C were used as a base material for the synthesis of geopolymer mortar. Eight molar sodium hydroxide solution mixed with sodium silicate solution was used as alkaline activator. For optimum geopolymerization, mortar was cured at sixty degree Celsius for twenty four hours duration. Results show different behavior of metakaolin replacement on compressive strength for two different types of fly ash based geopolymer mortar. Improvement in compressive strength was seen by addition of metakaolin in ASTM class F fly ash based geopolymer. On the other hand compressive strength was decreased abruptly in fly ash class C based geopolymer up to certain replacement level.

Download Full-text

COMPRESSIVE STRENGTH OF GEOPOLYMER MORTAR USING GROUND FERRONICKEL SLAG AND FLY ASH

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2020.7(1).mat-05 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Jhutan Chandra Kuri ◽

Md Nabi Newaz Khan ◽

Prabir Kumar Sarker

Keyword(s):

Stainless Steel ◽

Compressive Strength ◽

Fly Ash ◽

Nickel Alloy ◽

Strength Increase ◽

Reaction Products ◽

Huge Amount ◽

Alkaline Activator ◽

Ferronickel Slag

A huge amount of ferronickel slag is produced as a by-product of manufacturing ferronickel, which is used in stainless steel and nickel alloy. This paper presents the effect of using different percentages of ground ferronickel slag (GFNS) with fly ash (FA) on the workability and compressive strength of geopolymer mortar. A mixture of NaOH and Na2SiO3 solutions was used as the alkaline activator. It was found that the flow of fresh mortar decreased with the increase of GFNS content. This is attributed to the higher fineness and angular shape of GFNS particles as compared to spherical fly ash particles. The mortar cube specimens were heat-cured at 60 °C for 24 hours. The compressive strength of geopolymer mortar using 100% FA was 54 MPa and it increased by 17%, 21% and 36% for using 25%, 50% and 75% GFNS as fly ash replacement, respectively. The strength increase is attributed to the increase of Si/Al ratio by GFNS that favoured the production of alkali aluminosilicate reaction products.

Download Full-text

Effect of Fly Ash and Lime Treatment on Mechanical and Swell Properties of Dunkirk Dredged Sediments

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.250-253.755 ◽

2011 ◽

Vol 250-253 ◽

pp. 755-760

Author(s):

Dong Xing Wang ◽

Rachid Zentar ◽

Nor Edine Abriak ◽

Wei Ya Xu

Keyword(s):

Tensile Strength ◽

Fly Ash ◽

Base Material ◽

Lime Treatment ◽

Dredged Sediments ◽

Road Base ◽

Base Materials ◽

Dredged Materials ◽

Strength Tests ◽

Traditional Approaches

Traditional approaches such as ocean dumping and inland deposit are unsatisfactory for the management of dredged sediments, in the context of sustainable development. The solidified sediments with fly ash and lime as road base materials are preferred to conserve land and minimize impact to environment. A series of tests, such as compaction tests, tensile strength tests and swell tests, were performed to explore mechanical and swell properties of Dunkirk dredged materials. The fly ash contributes to the considerable increase in elastic modulus and the small increase in tensile strength in the presence of lime. Then the potential of treated sediments as road base material is evaluated. After immersion in water for 4 days, the addition of fly ash can induce a remarkable increase in swell percents in contrast with the lime-based sediments.

Download Full-text

The Relationship of NaOH Molarity, Na2SiO3/NaOH Ratio, Fly Ash/Alkaline Activator Ratio, and Curing Temperature to the Strength of Fly Ash-Based Geopolymer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.328-330.1475 ◽

2011 ◽

Vol 328-330 ◽

pp. 1475-1482 ◽

Cited By ~ 43

Author(s):

M. M. A. Abdullah ◽

H. Kamarudin ◽

M. Bnhussain ◽

I. Khairul Nizar ◽

A.R. Rafiza ◽

...

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Construction Industry ◽

Curing Temperature ◽

Test Results ◽

Compression Tests ◽

Naoh Solution ◽

Alkaline Activator ◽

Relationship Of ◽

The Relationship

Geopolymer, produced by the reaction of fly ash with an alkaline activator (mixture of Na2SiO3 and NaOH solutions), is an alternative to the use of ordinary Portland cement (OPC) in the construction industry. However, there are salient parameters that affecting the compressive strength of geopolymer. In this research, the effects of various NaOH molarities, Na2SiO3/NaOH ratios, fly ash/alkaline activator, and curing temperature to the strength of geopolymer paste fly ash were studied. Tests were carried out on 50 x 50 x 50 mm cube geopolymer specimens. Compression tests were conducted on the seventh day of testing for all samples. The test results revealed that a 12 M NaOH solution produced the highest compressive strength for the geopolymer. The combination mass ratios of fly ash/alkaline activator and Na2SiO3/NaOH of 2.0 and 2.5, respectively, produced the highest compressive strength after seven days. Geopolymer samples cured at 60 °C produced compressive strength as high as 70 MPa.

Download Full-text