Effects of various fineness moduli of fine aggregate on engineering properties of high‐performance concrete

2001 ◽  
Vol 24 (3) ◽  
pp. 289-300 ◽  
Author(s):  
Ta‐Peng Chang ◽  
Shi‐Hong Lin ◽  
Huang‐Chin Lin ◽  
Ping‐Ru Lin
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Engineering Properties ◽  
Fine Aggregate

Effect of Copper Slag as a Fine Aggregate on the Durability Characteristics of High-Performance Concrete (HPC) Containing Silica Fume

2020 ◽  
Vol 07 (02) ◽  
pp. 1-10
Author(s):  
Rizwan Ahmad Khan ◽  
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Copper Slag ◽  
Chloride Penetration ◽  
Interfacial Transition Zone ◽  
Fine Aggregate ◽  
Fresh Properties ◽  
Fine Aggregates ◽  
Effect Of Copper

This paper investigates the fresh and durability properties of the high-performance concrete by replacing cement with 15% Silica fume and simultaneously replacing fine aggregates with 25%, 50%, 75% and 100% copper slag at w/b ratio of 0.23. Five mixes were analysed and compared with the standard concrete mix. Fresh properties show an increase in the slump with the increase in the quantity of copper slag to the mix. Sorptivity, chloride penetration, UPV and carbonation results were very encouraging at 50% copper slag replacement levels. Microstructure analysis of these mixes shows the emergence of C-S-H gel for nearly all mixes indicating densification of the interfacial transition zone of the concrete.

scholarly journals Abrasion Resistance of Ultra-High-Performance Concrete for Railway Sleepers

2021 ◽  
Author(s):  
Ariful Hasnat ◽  
Nader Ghafoori
Keyword(s):  
Prestressed Concrete ◽  
Abrasion Resistance ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Positive Influence ◽  
Cementitious Material ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Ultra High Performance Concrete

AbstractThis study aimed to determine the abrasion resistance of ultra-high-performance concretes (UHPCs) for railway sleepers. Test samples were made with different cementitious material combinations and varying steel fiber contents and shapes, using conventional fine aggregate. A total of 25 UHPCs and two high-strength concretes (HSCs) were selected to evaluate their depth of wear and bulk properties. The results of the coefficient of variation (CV), relative gain in abrasion, and abrasion index of the studied UHPCs were also obtained and discussed. Furthermore, a comparison was made on the resistance to wear of the selected UHPCs with those of the HSCs typically used for prestressed concrete sleepers. The outcomes of this study revealed that UHPCs displayed excellent resistance against abrasion, well above that of HSCs. Amongst the utilized cementitious material combinations, UHPCs made with silica fume as a partial replacement of cement performed best against abrasion, whereas mixtures containing fly ash showed the highest depth of wear. The addition of steel fibers had a more positive influence on the abrasion resistance than it did on compressive strength of the studied UHPCs.

scholarly journals Effect of Mineral Aggregates and Chemical Admixtures as Internal Curing Agents on the Mechanical Properties and Durability of High-Performance Concrete

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2090 ◽  
Author(s):  
Francisco Javier Vázquez-Rodríguez ◽  
Nora Elizondo-Villareal ◽  
Luz Hypatia Verástegui ◽  
Ana Maria Arato Tovar ◽  
Jesus Fernando López-Perales ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Ions ◽  
Internal Curing ◽  
Fine Aggregate ◽  
Pumice Stone ◽  
Chemical Admixtures ◽  
Mineral Aggregates

In the present work, the effect of mineral aggregates (pumice stone and expanded clay aggregates) and chemical admixtures (superplasticizers and shrinkage reducing additives) as an alternative internal curing technique was investigated, to improve the properties of high-performance concrete. In the fresh and hardened state, concretes with partial replacements of Portland cement (CPC30R and OPC40C) by pulverized fly ash in combination with the addition of mineral aggregates and chemical admixtures were studied. The physical, mechanical, and durability properties in terms of slump, density, porosity, compressive strength, and permeability to chloride ions were respectively determined. The microstructural analysis was carried out by scanning electronic microscopy. The results highlight the effect of the addition of expanded clay aggregate on the internal curing of the concrete, which allowed developing the maximum compressive strength at 28 days (61 MPa). Meanwhile, the replacement of fine aggregate by 20% of pumice stone allowed developing the maximum compressive strength (52 MPa) in an OPC-based concrete at 180 days. The effectiveness of internal curing to develop higher strength is attributed to control in the porosity and a high water release at a later age. Finally, the lowest permeability value at 90 days (945 C) was found by the substitutions of fine aggregate by 20% of pumice stone saturated with shrinkage reducing admixture into pores and OPC40C by 15% of pulverized fly ash. It might be due to impeded diffusion of chloride ions into cement paste in the vicinity of pulverized fly ash, where the pozzolanic reaction has occurred. The proposed internal curing technology can be considered a real alternative to achieve the expected performance of a high-performance concrete since a concrete with a compressive strength range from 45 to 67 MPa, density range from 2130 to 2310 kg/m3, and exceptional durability (< 2000 C) was effectively developed.

The Durability Study of Concrete in Sulfate Environment

2012 ◽  
Vol 204-208 ◽  
pp. 3137-3141
Author(s):  
Hong Xia Qiao ◽  
Yu Li ◽  
Zhong Mao He ◽  
Jin Mei Dong
Keyword(s):  
Portland Cement ◽  
High Performance ◽  
Elastic Moduli ◽  
High Performance Concrete ◽  
Salt Resistance ◽  
Fine Aggregate ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Sulfate Solutions ◽  
Better Than

Aiming at determining the durability of concrete in very salty regions, this study examines the performance of various high performance fine aggregate concretes in a sulfate environment, such as high performance concrete inside a composite additive, and Portland cement concrete and sulfate resistant cement concrete, all of which experienced dry-wet cycles in sodium sulfate solutions. By examining the changes of elastic moduli and analyzing the SEM of the concrete, this paper has found that the salt resistance of sulfate resistant cement concrete is no better than that of Portland cement concrete in the extremely aggressive dry-wet cycle environment but high performance concrete containing a composite additive has better resistance in a sulfate environment. Besides, the composite additive can create the environment for a second hydration to reduce the amount of Ca(OH)2 inside the concrete, and build additional C-S-H gel to reform the microstructure of concrete effectively. Finally, the paper offers some advice for mixing concrete in salt regions.

Applying Back-Propagation Neural Network for Estimating the Slump of Concrete

2013 ◽  
Vol 651 ◽  
pp. 986-989
Author(s):  
Chin Ming Kao ◽  
Li Chen ◽  
Chang Huan Kou ◽  
Shih Wei Ma
Keyword(s):  
Neural Network ◽  
High Performance ◽  
High Performance Concrete ◽  
Linear Regression Analysis ◽  
Back Propagation ◽  
Nonlinear Function ◽  
Multiple Linear Regression Analysis ◽  
Back Propagation Neural Network ◽  
Fine Aggregate ◽  
Furnace Slag

This paper proposes the back-propagation neural network (BPN) and applies it to estimate the slump of high-performance concrete (HPC). It is known that HPC is a highly complex material whose behaviour is difficult to model, especially for slump. To estimate the slump, it is a nonlinear function of the content of all concrete ingredients, including cement, fly ash, blast furnace slag, water, superplasticizer, and coarse and fine aggregate. Therefore, slump estimation is set as a function of the content of these seven concrete ingredients and additional four important ratios. The results show that BPN obtains a more accurate mathematical equation through learning procedures which outperforms the traditional multiple linear regression analysis (RA), with lower estimating errors for predicting the HPC slump.

Manufacture of High-Performance Concrete Made with Powdered Polyester Resin Waste and Carboxylic-Ester Based Superplasticizer

2015 ◽  
Vol 1129 ◽  
pp. 523-529 ◽  
Author(s):  
A. Rodríguez ◽  
Pablo Luis Campos ◽  
J. Garabito ◽  
Juan García ◽  
Isabel Santamaría
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Polyester Resin ◽  
High Performance Concrete ◽  
The Other ◽  
Partial Substitution ◽  
Fine Aggregate ◽  
Hardened State ◽  
Aggregate Material ◽  
Research Show

A high-performance concrete design is presented that incorporates powdered polyester resin waste as a fine aggregate material in partial substitution of sand, with additions of both a superplasticizer based on carboxylic ethers and silica fume. The potential application of the powdered polyester resin and its properties as an aggregate are both analysed as well as the mechanical behaviour, in both the fresh and the hardened states, of the concrete. Both the flexural and the compressive strength of the concrete were shown to depend on the amount of waste used in substitution of the sand. The results of the research show that the designed concrete reaches the resistances of a high performance concrete with values ​​above 50 MPa. On the other hand, the rest of its properties are equivalents, both in the fresh and hardened state, proportional to the amount of powdered polyester resin that is added. However, to achieve this, the use of superplasticizers additives and admixtures of silica fume is necessary.

Studies on ultra high performance concrete incorporating copper slag as fine aggregate

2015 ◽  
Vol 77 ◽  
pp. 233-240 ◽  
Author(s):  
P.S. Ambily ◽  
C. Umarani ◽  
K. Ravisankar ◽  
Prabhat Ranjan Prem ◽  
B.H. Bharatkumar ◽  
...  
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Copper Slag ◽  
Fine Aggregate ◽  
Ultra High Performance Concrete
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