scholarly journals The Stabilization of Weathered Dolerite Aggregates with Cement, Lime, and Lime Fly Ash for Pavement Construction

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Felix N. Okonta ◽  
Oluwapelumi O. Ojuri
Keyword(s):  
Fly Ash ◽  
Dry Weight ◽  
Linear Functions ◽  
Experimental Program ◽  
Rural Roads ◽  
Low Volume Roads ◽  
Class B ◽  
Curing Methods ◽  
Water Curing ◽  
Pavement Construction

An experimental program was performed on weathered dolerite specimens stabilized by adding varying percentages of cement (4, 8, 12, and 16) % and lime (6 and 12) % and a combination of lime and fly ash (6% lime + 12% Fly ash and 12% lime + 12% Fly ash) % by dry weight of soil. The strength was examined under three different curing methods, namely, membrane curing (MBC), alternate moist-air curing (MAC), and water curing (WAC), by conducting unconfined compressive strength (UCS) tests. Simple polynomial and linear functions (regression models) were used to define the relationships between the variables investigated. Membrane curing (MBC) gave results close enough to the water curing (WAC) to indicate that it can be confidently used on the field during pavement construction. From the results obtained, for class B (interurban collector and major rural roads) pavement construction, addition of 8% cement was recommended for road base construction with stabilized WDA. Also the addition of 12 + 12% Lime and Fly Ash was recommended for road subbase construction with stabilized WDA. Stabilized WDA against the prejudiced myths would perform satisfactorily for base and subbase construction in both heavily trafficked and low volume roads with economic quantities of cement, lime, and fly ash in South Africa.

scholarly journals Effect of Curing Method on Concrete with Palm Oil Fuel Ash as a Cement Replacement

2018 ◽  
Vol 7 (3.36) ◽  
pp. 68 ◽  
Author(s):  
Wael Elleithy ◽  
Chin Chee Fung ◽  
Jayaprakash Jaganathan ◽  
Teck Leong Lau ◽  
Mohammed Parvez Anwar
Keyword(s):  
Flexural Strength ◽  
Palm Oil ◽  
Experimental Program ◽  
Palm Oil Fuel Ash ◽  
Cement Replacement ◽  
Fuel Ash ◽  
Curing Methods ◽  
Water Curing ◽  
Curing Method ◽  
Oil Fuel

In this paper, the effect of different curing methods on the strength of concrete with palm oil fuel ash as a cement replacement is investigated. An experimental program was carried out to study the effect of five different curing methods, i.e., water curing (WC), air curing (AC), plastic-wrapped curing (PC), oven and water curing (OWC), and oven and air curing (OAC), on the compressive and flexural strengths of palm oil fuel ash concrete (POFA20), where 20% of the cement was replaced by palm oil fuel ash. The results obtained from this investigation showed that POFA20-WC has the highest compressive and flexural strength, whilst POFA20-AC has the lowest at the age of 28 days. Both of the POFA20-OWC and POFA20-OAC have the highest compressive and flexural strength at the age of 3 days. The results emphasize the positive effect of oven curing procedure to achieve high compressive and flexural strength at early stage. However, the rate of hydration started to decrease at later stages, which leads to much lower rate of gaining strength in POFA20-OWC and POFA20-OAC. Water curing method is thus recommended in the construction industry except for extraordinary requirements and/or circumstances.   

Early Age Performance of Continuously Reinforced Concrete Pavement with Different Types of Aggregate

1997 ◽  
Vol 1568 (1) ◽  
pp. 35-43
Author(s):  
Yoon-Ho Cho ◽  
Terry Dossey ◽  
B. Frank Mccullough
Keyword(s):  
Reinforced Concrete ◽  
Field Test ◽  
Field Tests ◽  
Concrete Pavement ◽  
Crack Spacing ◽  
Winter Period ◽  
Thermal Coefficient ◽  
Curing Methods ◽  
Pavement Construction ◽  
New Variables

The effect of coarse aggregate on pavement performance has been attributed to the volume of aggregate used in pavement construction. The different patterns of crack development for limestone (LS) and siliceous river gravel (SRG) are a typical example of aggregate-induced variable performance in continuously reinforced concrete pavement (CRCP). An attempt was made to find a reasonable solution for pavements with SRG. As a way to solve the performance problem observed from the SRG pavement, a blended aggregates mixture was suggested. Laboratory and field tests were performed to check the feasibility of their application in pavements. From the laboratory test, a 50:50 blending ratio was suggested after considering the effect on tensile strength and thermal coefficient of expansion. Field test sections were also constructed to verify previous performance observations for the two aggregates and to provide performance data for new variables such as blended aggregates and special curing methods. Unexpectedly, the blended mixture did not improve the performance of SRG pavement; rather it experienced worse cracking than SRG alone. A controlled experiment with additional field test sections is needed to verify or disprove this finding. The only definitive finding was that selection of aggregate in the concrete pavement is a vital consideration for the design of the pavement. The CRCP8 analytical program reasonably predicted crack spacing for both SRG and LS pavements, predicting mean crack spacing of 0.99 m (3.25 ft) for SRG and 1.98 m (6.41 ft) for the limestone. These values are somewhat below the actual spacing observed at 100 days. Data collected after the first winter period will be required to calibrate the program.

Recycling of Waste Concrete and Fly Ash for Recycled Aggregate Concrete: Fundamental Characteristics Evaluation

2009 ◽  
Vol 620-622 ◽  
pp. 255-258 ◽  
Author(s):  
Cheol Woo Park
Keyword(s):  
Fly Ash ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Recycled Concrete Aggregate ◽  
Aggregate Concrete ◽  
Waste Concrete

As the amount of waste concrete has been increased and recycling technique advances, this study investigates the applicability of recycled concrete aggregate for concrete structures. In addition fly ash, the industrial by-product, was considered in the concrete mix. Experimental program performed compressive strength and chloride penetration resistance tests with various replacement levels of fine recycled concrete aggregate and fly ash. In most case, the design strength, 40MPa, was obtained. It was known that the replacement of the fine aggregate with fine RCA may have greater influence on the strength development rather than the addition of fly ash. It is recommended that when complete coarse aggregate is replaced with RCA the fine RCA replacement should be less than 60%. The recycled aggregate concrete can achieve sufficient resistance to the chloride ion penetration and the resistance can be more effectively controlled by adding fly ash. It I finally conclude that the recycled concrete aggregate can be successfully used in the construction field and the recycling rate of waste concrete and flay ash should be increased without causing significant engineering problems.

Systematic approach to assessing the applicability of fly-ash-based geopolymer for clay stabilization

2020 ◽  
Vol 57 (9) ◽  
pp. 1356-1368 ◽  
Author(s):  
Hayder H. Abdullah ◽  
Mohamed A. Shahin ◽  
Megan L. Walske ◽  
Ali Karrech
Keyword(s):  
Fly Ash ◽  
Systematic Approach ◽  
Soil Stabilization ◽  
Ground Improvement ◽  
Experimental Program ◽  
Attractive Alternative ◽  
Chemical Additives ◽  
Soil Mineralogy ◽  
Problematic Soils ◽  
Ph Level

Traditional soil stabilization by chemical additives such as cement and lime is a well-established technique for ground improvement of problematic soils. However, with the advantage of lower carbon emission and energy consumption, fly-ash-based geopolymer has recently become an attractive alternative to traditional stabilizers. Nevertheless, the literature lacks systemic approaches that assist engineers to apply this promising binder for soil stabilization, including the proper dosages required for an effective treatment. This paper introduces a systematic approach to assess the applicability of fly-ash-based geopolymer for stabilization of clay soils, through a comprehensive experimental program where engineered and natural clays were examined and evaluated, including soil compaction, plasticity, compressive strength, durability, pH level, and impact of pulverization. The results revealed several factors that influence the level of enhancement of geopolymer-treated clays, including the soil mineralogy, plasticity–activity properties, geopolymer concentration, curing time, and pulverization.

scholarly journals Utilization of Red Mud-Fly Ash Reinforced with Cement in Road Construction Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Sarath Chandra K ◽  
Krishnaiah S ◽  
Kibebe Sahile
Keyword(s):  
Fly Ash ◽  
Red Mud ◽  
Industrial Waste ◽  
Construction Material ◽  
Road Construction ◽  
Dry Weight ◽  
Strength Properties ◽  
Environmental Threat ◽  
The Right ◽  
The Impact

Industrialization is the key to the growth of any country’s economy. However, on the other hand, the production of industrial waste is increasing enormously, which adversely impacts the environment and natural resources. Red mud is also a widespread industrial waste produced during aluminium extraction from bauxite ore in Bayer’s process. Red mud is a highly alkaline material that creates a massive environmental threat in nature. To reduce the impact of this solid waste material, the ideal method is to use it in construction works with appropriate stabilization. This study envisages the strength properties of red mud with fly ash and cement to use it as a road construction material in the subgrade. The influence of fly ash and cement on improving the strength properties of red mud was studied in detail by replacing red mud with 10%, 20%, and 30% with fly ash and 1%, 3%, and 5% of cement to its dry weight. The CBR (California bearing ratio) value was increased from 1.58% to 11.6% by stabilizing red mud with fly ash and cement, which can be used as a road construction material. The UCS (unconfined compressive strength) of red mud was increased from 825 kPa to 2340 kPa upon curing for 28 days with the right mix of fly ash and cement. Along with the strength properties, the chemical analysis of leachate for the best suitable mix was performed according to the TCLP method to understand the hazardous materials present in the red mud when it is injected as ground material. Both strength properties and the leachate characteristics prove that the red mud with suitable fly ash and cement is an excellent material in road constructions.

scholarly journals Industrial Wastes in Soil Improvement

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
G. V. Rama Subbarao ◽  
D. Siddartha ◽  
T. Muralikrishna ◽  
K. S. Sailaja ◽  
T. Sowmya
Keyword(s):  
Fly Ash ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Cost Effective ◽  
Dry Weight ◽  
Soil Improvement ◽  
Geotechnical Properties ◽  
Point Of View ◽  
Industrial Wastes ◽  
Engineering Structures

Soil existing at a particular site may not be appropriate for construction of engineering structures. The present study made an attempt to enhance the geotechnical properties of a soil replaced with industrial wastes having pozzolanic value like rice husk ash (RHA) and fly ash (FA). Soil is replaced with RHA in 2%, 4%, and 6% to dry weight of soil. It is observed that soil replaced with 4% RHA is the optimum for the soil used in this study from geotechnical point of view. To know the influence of fly ash, soil is further replaced with 4% FA along with 4% RHA. It is found that results of soil replacement by both RHA and FA proved to be soil modification and not the improvement. Hence, a cost-effective accelerator like lime is used for further replacing the above soil-4%, RHA-4% FA mix. The optimum lime content is found to be 4%.

Macroscopic and Microscopic Properties of High Performance Concrete with Partial Replacement of Cement by Fly Ash

2019 ◽  
Vol 292 ◽  
pp. 108-113 ◽  
Author(s):  
Josef Fládr ◽  
Petr Bílý ◽  
Roman Chylík ◽  
Zdeněk Prošek
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Partial Replacement ◽  
Experimental Program ◽  
Second Phase ◽  
Depth Of Penetration ◽  
Cement Replacement

The paper describes an experimental program focused on the research of high performance concrete with partial replacement of cement by fly ash. Four mixtures were investigated: reference mixture and mixtures with 10 %, 20 % and 30 % cement weight replaced by fly ash. In the first stage, the effect of cement replacement was observed. The second phase aimed at the influence of homogenization process for the selected 30% replacement on concrete properties. The analysis of macroscopic properties followed compressive strength, elastic modulus and depth of penetration of water under pressure. Microscopic analysis concentrated on the study of elastic modulus, porosity and mineralogical composition of cement matrix using scanning electron microscopy, spectral analysis and nanoindentation. The macroscopic results showed that the replacement of cement by fly ash notably improved compressive strength of concrete and significantly decreased the depth of penetration of water under pressure, while the improvement rate increased with increasing cement replacement (strength improved by 18 %, depth of penetration by 95 % at 30% replacement). Static elastic modulus was practically unaffected. Microscopic investigation showed impact of fly ash on both structure and phase mechanical performance of the material.

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