Influence of Particle Size Distribution of Fly Ash on Compressive Strength and Durability of Portland Cement Concrete

2011 ◽  
Vol 685 ◽  
pp. 211-215
Author(s):  
Jian Ping Zhu ◽  
Qi Lei Guo ◽  
Dong Xu Li ◽  
Cun Jun Li
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plants ◽  
Reference Sample ◽  
Chloride Penetration ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Strength And Durability ◽  
Different Content ◽  
Better Than

The Present Research Investigates the Compressive and Durable Properties of Concretes with Fly Ash (FA), a by-Product of Coal-Fired Power Plants. for this Purpose, a Reference Sample and Twenty-one Concretes Containing FA Were Tested. the FA Was Sieved to 200, 300, and 400 Mesh. then FA Was Mixed into Concrete with Different Content. Compressive Strength at 7 and 28 Days, and Chloride Penetration Properties Were Measured. it Is Concluded that FA Can Be Used in the Production of Concrete. in Addition, the FA Concretes Present Satisfactory Physical Properties. when Proper Amount of FA Were Added the Concrete Properties Can Be Better than the Blank one.

Influence of Steel Slag on Compressive Strength and Durability of Concrete

2011 ◽  
Vol 704-705 ◽  
pp. 1051-1054
Author(s):  
Jian Ping Zhu ◽  
Qi Lei Guo ◽  
Xiang Gao ◽  
Dong Xu Li
Keyword(s):  
Compressive Strength ◽  
Research Study ◽  
Coarse Aggregate ◽  
Reference Sample ◽  
Steel Slag ◽  
Concrete Durability ◽  
Slag Powder ◽  
Steel Slag Powder ◽  
Strength And Durability ◽  
Better Than

The present research study investigates the compressive and durable properties of concretes with steel slag, a by-product of the conversion process of iron to steel. For this purpose, a reference sample and twenty-four concretes containing steel slag were tested. The steel slag fraction used was “5–20 mm”, and the surface area of steel slag powder was 450m2/kg. Compressive strength at 7 and 28 days, and chloride penetration properties were measured. It is concluded that steel slag can be used in the production of concrete. In addition, the steel slag concretes present satisfactory physical properties. When proper amount of steel slag powder and steel slag fraction were used the concrete properties can be better than the blank one. Keywords: Steel slag, cement, coarse aggregate, concrete, durability

Effect of Specimen Size and Curing Condition on the Compressive Strength of Alkali-Activated Concrete

2017 ◽  
Vol 2629 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Robert James Thomas ◽  
Sulapha Peethamparan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Specimen Size ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Slag Cement ◽  
Fly Ash Concrete ◽  
Activated Slag ◽  
Alkali Activated Concrete ◽  
Alkali Activated

Alkali-activated concrete is a rapidly emerging sustainable alternative to portland cement concrete. The compressive strength behavior of alkali-activated concrete has been reported by various studies to a limited extent, but these discussions have been based on minimal evidence. Furthermore, although it is known that specimen size has a distinct effect on the apparent compressive strength of concrete, this effect has yet to be modeled for alkali-activated concrete. This paper presents the results of a comprehensive study of the effects of curing condition (i.e., moist-cured at ambient temperature for 28 days or heat-cured at 50çC for 48 h) and specimen size on the compressive strength of sodium silicate–activated fly ash and slag cement concrete. The heat-cured strength of alkali-activated slag cement concrete was linearly related to the moist-cured strength; the former was about 5% greater than the latter. Heat curing also improved the strength of alkali-activated fly ash concrete, although the effect was greatly magnified for lower-strength mixtures and was much less significant at higher strengths. Existing size effect laws employed for portland cement concrete proved reasonably accurate in describing the effect of specimen size on the apparent strength of alkali-activated slag cement concrete. However, these existing models greatly underestimated the size effect in alkali-activated fly ash concrete; the authors suggest that this finding was the result of significant microcracking in the alkali-activated fly ash concrete.

Development of sustainable construction material from fly ash class C

2020 ◽  
Vol 18 (6) ◽  
pp. 1615-1640
Author(s):  
Eric Asa ◽  
Monisha Shrestha ◽  
Edmund Baffoe-Twum ◽  
Bright Awuku
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Alkaline Solution ◽  
Sustainable Construction ◽  
Geopolymer Concrete ◽  
Curing Time ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Content Type

Purpose Environmental issues caused by the production of Portland cement have led to it being replaced by waste materials such as fly ash, which is more economical and safer for the environment. Also, fly ash is a material with sustainable properties. Therefore, this paper aims to focus on the development of sustainable construction materials using 100% high-calcium fly ash and potassium hydroxide (KOH)-based alkaline solution and study the engineering properties of the resulting fly ash-based geopolymer concrete. Laboratory tests were conducted to determine the mechanical properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In phase I of the study, carbon nanotubes (CNTs) were added to determine their effect on the strength of the geopolymer mortar. The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce similar (comparable) strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates a considerable amount of heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond was unable to form a stronger bond. This study also determined that the addition of CNTs to the mix makes the geopolymer concrete tougher than the traditional concrete without CNT. Design/methodology/approach Tests were conducted to determine properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In Phase I of the study, CNTs were studied to determine their effect on the strength of the geopolymer mortar. Findings The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce the same strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates too much heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond. This study also determined that the addition of CNTs to the mix makes the concrete tougher than concrete without CNT. Originality/value This study was conducted at the construction engineering and management concrete laboratory at North Dakota State University in Fargo, North Dakota. All the experiments were conducted and analyzed by the authors.

Proportioning of concrete mixes incorporating fly ash

1976 ◽  
Vol 3 (1) ◽  
pp. 68-82 ◽  
Author(s):  
Ram S. Ghosh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio

A method is described for proportioning fly ash concretes to produce similar compressive strengths as normal Portland cement concrete at 3, 7, 28, and 90 days. The method is primarily based on the Abrams' law relating compressive strength and water–cement ratio. Curves are also presented, for estimating the most economical fly ash to cement ratio for a particular strength and cost of fly ash.

Review on Alkali-Activated Fly Ash Based Geopolymer Concrete

2016 ◽  
Vol 841 ◽  
pp. 162-169 ◽  
Author(s):  
Kefiyalew Zerfu ◽  
Januarti Jaya Ekaputri
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Construction Material ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Carbon Credit ◽  
Cement Concrete ◽  
Carbon Dioxide Co2 ◽  
Alkali Activated ◽  
Better Than

Due to environmental pollution form cement industries, some efforts for alternative construction material are increasing. Recently, geopolymer concrete has drawn attention of researchers and engineers because of its lower carbon print and better mechanical property over Portland cement concrete. According to previous studies, geopolymer concrete results almost up to 90% reduction in carbon dioxide (CO2) emission to atmosphere. Mechanical properties of geopolymer concrete such as compressive strength, durability, sulfate resistance, early strength and low shrinkage are better than Portland cement concrete. In addition, the appropriate usage of one ton of fly ash earns one carbon-credit redemption value of about 20 Euros, and hence earned monetary benefits through carbon-credit trade.Therefore, this paper presents a review on the fly ash-based geopolymer concrete. The paper mainly covers composition, mixing and curing process, benefits, limitations and applications of alkali activated fly ash based geopolymer concrete.

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

2021 ◽  
Vol 323 ◽  
pp. 8-13
Author(s):  
Jadambaa Temuujin ◽  
Damdinsuren Munkhtuvshin ◽  
Claus H. Ruescher
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Power Stations ◽  
Thermal Power Stations ◽  
Coal Ashes ◽  
By Products

With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.

Low Cement/High Fly Ash Concretes: Their Properties and Response to Chemical Admixtures

1987 ◽  
Vol 113 ◽  
Author(s):  
V. H. Dodson
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Calcium Hydroxide ◽  
Pozzolanic Reaction ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Fly Ashes ◽  
Chemical Admixtures ◽  
Reaction With Water

ABSTRACTIn practice, the amount of fly ash added to portland cement concrete varies depending upon the desired end properties of the concrete. Generally, when a given portland cement concrete is redesigned to include fly ash, between 10 and 50% of the cement is replaced by a volume of fly ash equal to that of the cement. Sometimes as much as twice the volume of the cement replaced, although 45.4 kg (100 lbs) of cement will only produce enough calcium hydroxide during its reaction with water to react with about 9 kg (20 lbs) of a typical fly ash. The combination of large amounts of certain fly ashes with small amounts of portland cement in concrete has been found to produce surprisingly high compressive strengths, which cannot be accounted for by the conventional “pozzolanic reaction”. Ratios of cement to fly ash as high as 1:15 by weight can produce compressive strengths of 20.7 MPa (3,000 psi) at I day and over 41.4 MPa (6,000 psi) at 28 days. Methods of identifying these “hyperactive” fly ashes along with some of the startling results, with and without chemical admixtures are described.

Sign in / Sign up

Export Citation Format

Share Document