Sustainable and Economical Precast and Prestressed Concrete Using Fly Ash as a Cement Replacement

2011 ◽  
Vol 23 (6) ◽  
pp. 789-792 ◽  
Author(s):  
John Zachar
Keyword(s):  
Fly Ash ◽  
Prestressed Concrete ◽  
Cement Replacement

Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh
Keyword(s):  
Fly Ash ◽  
Concrete Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Chloride Permeability ◽  
Cement Replacement ◽  
Fine Grained ◽  
Granulated Blast Furnace Slag ◽  
Compressive Strength Test ◽  
Economic Ground

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

Reusing leached fly ash as a cement replacement

2018 ◽  
Vol 171 (6) ◽  
pp. 286-295 ◽  
Author(s):  
Fátima Arroyo Torralvo ◽  
Constantino Fernandez-Pereira ◽  
Carlos Leiva Fernandez ◽  
Yolanda Luna Galiano ◽  
Celia García Arenas ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cement Replacement

scholarly journals Long-Term Vibration Monitoring of the Effects of Temperature and Humidity on PC Girders with and without Fly Ash considering ASR Deterioration

2017 ◽  
Vol 2017 ◽  
pp. 1-23
Author(s):  
Tuan Minh Ha ◽  
Saiji Fukada ◽  
Kazuyuki Torii
Keyword(s):  
Fly Ash ◽  
Prestressed Concrete ◽  
Weather Conditions ◽  
Element Model ◽  
Vibration Monitoring ◽  
Mode Shapes ◽  
Numerical Verification ◽  
Evaluation Procedures ◽  
Temperature And Humidity ◽  
Vibration Responses

Structural responses have been used as inputs in the evaluation procedures of civil structures for years. Apart from the degradation of a structure itself, changes in the environmental conditions affect its characteristics. For adequate maintenance, it is necessary to quantify the environment-induced changes and discriminate them from the effects due to damage. This study investigates the variation in the vibration responses of prestressed concrete (PC) girders, which were deteriorated because of the alkali–silica reaction (ASR), concerning ambient temperature and humidity. Three PC girders were exposed to outdoor weather conditions outside the laboratory, one of which had a selected amount of fly ash in its mixture to mitigate the ASR. The girders were periodically vibration tested for one and a half years. It was found that when the temperature and humidity increased, the frequencies and damping ratios decreased in proportion. No apparent variation in the mode shapes could be identified. A finite element model was proposed for numerical verification, the results of which were in good agreement with the measured changes in the natural frequencies. Moreover, the different dynamic performances of the three specimens indicated that the fly ash significantly affected the vibrations of the PC girders under ASR deterioration.

scholarly journals Properties of oil palm shell lightweight aggregate concrete containing fly ash as partial cement replacement

2020 ◽  
Vol 849 ◽  
pp. 012048
Author(s):  
Khairunisa Muthusamy ◽  
Mohamad Safwan Jaafar ◽  
Nili Wahida Azhar ◽  
Nurazzimah Zamri ◽  
Nadiah Samsuddin ◽  
...  
Keyword(s):  
Fly Ash ◽  
Oil Palm ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Cement Replacement ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Partial Cement Replacement

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.

An improved basis for characterizing the suitability of fly ash as a cement replacement agent

2017 ◽  
Vol 100 (10) ◽  
pp. 4785-4800 ◽  
Author(s):  
Tandré Oey ◽  
Jason Timmons ◽  
Paul Stutzman ◽  
Jeffrey W. Bullard ◽  
Magdalena Balonis ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cement Replacement

scholarly journals Development of Mix Designs for Minimally Refined Reclaimed Asphalt Pavement (RAP) Concrete for Florida Concrete Test Road

2018 ◽  
Vol 10 (8) ◽  
pp. 2598 ◽  
Author(s):  
Sangyoung Han ◽  
Hung-Wen Chung ◽  
Thanachart Subgranon ◽  
Mang Tia
Keyword(s):  
Fly Ash ◽  
Asphalt Pavement ◽  
Preliminary Test ◽  
American Concrete Institute ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Cement Replacement ◽  
Florida Department ◽  
Test Road ◽  
Pavement Concrete

The main objective was to develop mix designs for concrete incorporating minimally processed reclaimed asphalt pavement (RAP) materials to be used in the Florida Concrete Test Road. The laboratory program was conducted in two phases. Phase I involved testing of twelve (12) trial mixes to identify feasible mixes which could meet the Florida Department of Transportation (FDOT) specification requirements for pavement concrete. Based on the preliminary test results from the trial mixes, ten (10) production mixes were identified and evaluated more extensively in Phase II to establish the optimum concrete mixes incorporating RAP to be recommended. Concrete mixtures, with 0% to 40% RAP as aggregate replacement and using 20% fly ash and 50% slag as cement replacement, were designed using the optimized aggregate gradation (OAG) technique instead of the American Concrete Institute (ACI) method. Among the RAP concrete evaluated, the 20% RAP concrete mixes with 0%, 20% fly ash, and 50% slag as cement replacement were able to meet Florida Department of Transportation’s (FDOT) over-design compressive strength of 29 MPa (4200 psi) at 28 days. Using 20% and 40% RAP in concrete could result in saving in the total cost of aggregate by 9% and 17%, respectively. When the RAP is not refined (e.g., no washing of RAP, and no separating of coarse and fine portions), it is recommended that 20% of RAP can be used as aggregate replacement in pavement concrete.

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