The Effect of Fly Ash on Water Transport of Concrete in Dry State

2011 ◽  
Vol 335-336 ◽  
pp. 1190-1194
Author(s):  
Xiong Wen Zhang ◽  
Lei Jiang ◽  
Guan Guo Liu
Keyword(s):  
Fly Ash ◽  
Water Transport ◽  
High Performance ◽  
Test Results ◽  
Paper Test ◽  
Environment Friendly ◽  
Promising Solution ◽  
Long Term Performance ◽  
Term Performance

Water transport is an important parameter that affects the long term performance and degradation of concrete greatly. Nowadays, adding fly ash is a promising solution to achieve high-performance, low-price and environment-friendly concrete. To characterize the effect of fly ash on water transport of concrete, especially in dry state, moisture variations and microstructure of concrete with different mix proportions were studied in this paper. Test results reveal that fly ash will increase the porosity of early curing concrete, the higher porosity leads to a faster evaporation, which accelerates the transport of water in cement based materials.

Practical Recycling Application of Power Plant Coal Ash for High Performance Shotcrete Material

2009 ◽  
Vol 620-622 ◽  
pp. 251-254
Author(s):  
Cheol Woo Park ◽  
Kyung Nam Kim
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Power Plants ◽  
Construction Material ◽  
Coal Ash ◽  
Test Results ◽  
Replacement Ratio ◽  
Long Term Performance ◽  
Term Performance

This study intends to increase the consumption of coal ash which is an industrial by-product from power plants. The coal ash used to be deposited in the ground and its recycling has been very poor comparing to the produced amount. This study aims to enhance practical application of coal ash as a shotcrete construction material. Derived were optimum mix proportions for high performance shotcrete using coal ash. In order to enhance long term performance, silica fume was also added. Experimental variables included replacement ratio of silica fume and coal ash. Compressive strength and potential hazardous contamination to soil were the primary factors in the performance evaluation. From the test results, when fly ash was replaced up to 10% of the cement, most required specifications were satisfied. Hazardous material content was shown to be well below the specifications. Therefore, when appropriate caution in handling is given in the field, it is strongly anticipated to increase the coal ash recycling as a shotcrete construction material.

scholarly journals Review on Development and Dental Applications of Polyetheretherketone-Based Biomaterials and Restorations

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 408 ◽  
Author(s):  
Ludan Qin ◽  
Shuo Yao ◽  
Jiaxin Zhao ◽  
Chuanjian Zhou ◽  
Thomas W. Oates ◽  
...  
Keyword(s):  
High Performance ◽  
Dental Resin ◽  
Oral Environment ◽  
Inert Surface ◽  
Oral Implant ◽  
Long Term Performance ◽  
Dental Applications ◽  
Term Performance ◽  
Orthopedic Applications

Polyetheretherketone (PEEK) is an important high-performance thermoplastic. Its excellent strength, stiffness, toughness, fatigue resistance, biocompatibility, chemical stability and radiolucency have made PEEK attractive in dental and orthopedic applications. However, PEEK has an inherently hydrophobic and chemically inert surface, which has restricted its widespread use in clinical applications, especially in bonding with dental resin composites. Cutting edge research on novel methods to improve PEEK applications in dentistry, including oral implant, prosthodontics and orthodontics, is reviewed in this article. In addition, this article also discusses innovative surface modifications of PEEK, which are a focus area of active investigations. Furthermore, this article also discusses the necessary future studies and clinical trials for the use of PEEK in the human oral environment to investigate its feasibility and long-term performance.

Study on Long Term Performance of Concrete of Slag-Alkali Higher Calcium Fly Ash

2006 ◽  
Vol 302-303 ◽  
pp. 98-104
Author(s):  
Ming Tang ◽  
Xiao Li
Keyword(s):  
Fly Ash ◽  
Orthogonal Design ◽  
Concrete Specimen ◽  
Mixture Ratio ◽  
Dispersion Degree ◽  
Set Up ◽  
Long Term Performance ◽  
Term Performance ◽  
Mixture Ratio Design

The slag-alkali is used to activate the activity of higher calsium fly ash. By the designs of the mixture ratio and the quadratic regression orthogonal design, the best combination is sought out. Several mixture factors which affect the rule of the concrete material properties and long term performance are researched. The mathematic models which are set up by the mixture ratio design with the quadralic regression orthogonal design can be effective. The precision is high. The strength of the concrete of slag-alkali fly ash was still increasing after 8 year. The dispersion degree of those specimens is small. The SEM photo of cracked specimen and early concrete specimen shows the surface of fly ash in 7 days concrete is slick and that in 8 years old specimen has been enwrapped tightly by much hydrate plant.

Long Term Performance of the SkyTrough Solar Concentrator

2012 ◽  
Author(s):  
David White ◽  
Alison Mason ◽  
Ryan Clark
Keyword(s):  
High Performance ◽  
Additional Data ◽  
Low Cost ◽  
Parabolic Trough ◽  
Optical Efficiency ◽  
Model Predictions ◽  
Electrical Generation ◽  
Long Term Performance ◽  
Term Performance

The SkyTrough is an advanced integrated parabolic trough concentrator designed for high performance and low cost to achieve economic objectives in the market for high grade heat for industrial processes and electrical generation. To achieve low cost, a comprehensive optimization process was carried out for every component based on the choice of low cost silvered polymer film as the reflector. To verify high performance, the optical efficiency of a single module was measured at the National Renewable Energy Lab (NREL), and a demonstration loop was constructed in December, 2009 at the SEGS-II solar power plant in Daggett, CA, USA. This paper compares operating data recorded over eighteen months for the commercial demonstration at the SEGS-II plant with model predictions based on the NREL efficiency measurement. The comparison demonstrates that the SkyTrough system will perform predictably over time. Additional data illustrating the good performance of the collector in wind, and the sustained reflectance of the mirror film, are presented.

scholarly journals Seasonal Performance Evaluation of Pavement Base Using Recycled Materials

2021 ◽  
Vol 13 (22) ◽  
pp. 12714
Author(s):  
Yang Zhang ◽  
Bora Cetin ◽  
Tuncer B. Edil
Keyword(s):  
Fly Ash ◽  
Recycled Concrete ◽  
Ride Quality ◽  
Concrete Aggregate ◽  
Traffic Loading ◽  
Pavement Base ◽  
Natural Aggregates ◽  
Long Term Performance ◽  
Term Performance

Using recycled pavement materials to construct new pavement base is currently an important construction strategy bringing improved sustainability. This study investigates the long-term performance of pavement bases constructed with recycled concrete aggregate (RCA), reclaimed asphalt pavement (RAP), and blends with natural aggregates in a seasonal frost region. The stabilization effect of fly ash on RAP was studied as well. In situ falling weight deflectometer (FWD) tests were routinely conducted to provide seasonal deflection data, which were used to back-calculate the layer modulus. Seasonal changes in the base layer modulus along with the pavement ride quality were monitored. One of the two lanes at the test sections was consistently subjected to traffic loading, whereas the other one was not. Findings from this field research indicated that after undergoing over 8 years of naturally seasonal freeze-thaw conditions, 100% RCA, 50% RCA, plus 50% natural aggregates, and 100% RAP, presented improved performance over 100% natural aggregates. However, 50% RAP blended with 50% natural aggregates performed comparably to natural aggregates only, and fly ash did not provide considerable improvement on the long-term performance of 50% RAP plus 50% natural aggregate base. Seasonal climatic variations turned out to affect pavement performance more critically than traffic loading.

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