Effects of fly ash and cement content on rheological, mechanical, and transport properties of high-performance self-compacting concrete

2012 ◽  
Vol 19 (4) ◽  
pp. 393-405 ◽  
Author(s):  
Mostafa Jalal ◽  
Esmaeel Mansouri
Keyword(s):  
Fly Ash ◽  
Transport Properties ◽  
Rheological Properties ◽  
High Performance ◽  
Cement Content ◽  
Chloride Ion ◽  
Flow Time ◽  
Capillary Absorption ◽  
Self Compacting Concrete ◽  
Funnel Flow

AbstractRheological, mechanical, and transport properties of high-performance self-compacting concrete (HPSCC) mixes with different cement contents and fly ash percentages are studied in this research. Different HPSCC mixtures were investigated with cement contents of 400, 450, and 500 kg/m3 and fly ash percentages of 5%, 10%, and 15%. In order to achieve an enhanced durability, the aggregate grading curve was modified and improved based on power 0.45 grading curve. For a better understanding of fly ash effect and comparison purposes, a constant water to binder ratio (w/b=0.38) was used. The rheological properties were observed through slump flow time and diameter and V-funnel flow time. Mechanical properties including compressive and splitting tensile strength were determined at 7, 28, and 90 days. A comprehensive transport investigation was carried out using water absorption, capillary absorption, chloride ion percentage, and resistivity tests. The results showed a desirable improvement in rheological properties, and the compressive strength improved by about 10% for 15% fly ash at 90 days. A relatively significant improvement was also considered in all transport properties by increasing the fly ash percentage and cement content, especially at higher ages.

Transport properties of high-performance cementitious composites incorporating micro and nano SiO2 into the binder

2012 ◽  
Vol 19 (4) ◽  
pp. 415-421 ◽  
Author(s):  
Mostafa Jalal
Keyword(s):  
Water Absorption ◽  
Transport Properties ◽  
High Performance ◽  
Chloride Penetration ◽  
Binder Content ◽  
Cementitious Composites ◽  
Capillary Absorption ◽  
Nano Silica ◽  
Self Compacting Concrete ◽  
Concrete Properties

AbstractIn this paper, transport properties of high-performance self-compacting concrete (SCC), as one of the important cementitious composites incorporating micro and nano silica (NS) (SiO2) into the binder, have been investigated. For this purpose, different mixtures were designed with different amounts of silica fume (SF) and NS admixtures. Different binder contents were also investigated to observe the binder content effect on the concrete properties. Corrosion behavior was evaluated by chloride penetration and resistivity tests. Water absorption and capillary absorption were also measured as other durability related properties. The results showed that water absorption, capillary absorption, and Cl ion percentage decreased rather significantly in the mixtures containing admixtures especially the blend of SF and NS. By addition of the admixtures, resistivity of the SCC mixtures increased, which can lead to reduction of corrosion probability.

A Study on the Influence of Coarse Aggregate on Rheological Properties of Self-Compacting Concrete

2014 ◽  
Vol 633 ◽  
pp. 130-135
Author(s):  
Yu Chuan Jiang ◽  
Da Huo ◽  
Hai Wen Teng ◽  
Jin E Xu
Keyword(s):  
Particle Size ◽  
Rheological Properties ◽  
Coarse Aggregate ◽  
Volume Ratio ◽  
Flow Time ◽  
Self Compacting Concrete ◽  
Slump Flow ◽  
Binder Ratio ◽  
Funnel Flow ◽  
Water Binder Ratio

This paper presences the influence of coarse aggregate-space coefficient on the rheological properties of self-compacting concrete (SCC). The results indicate that coarse aggregate-space coefficient has significant influence on slump flow and V-funnel flow time of SCC, when the maximum aggregate particle size is 16mm and the volume ratio of sand and motor is 0.43, meanwhile water binder ratio is 0.38. The higher the coarse aggregate-space coefficient, the lager the slump flow, the shorter the V-funnel flow time. The range of coarse aggregate-space coefficient of SCC is suitable for 1.31~1.58 under the condition of the paper. The suitable range can guarantee excellent rheological properties and stability of SCC mixture. There is little effect of coarse aggregate-space coefficient on compressive strength in this paper tests.

Test and Study on Green High-Performance Marine Concrete Containing Ultra-Fine Limestone Powder

2013 ◽  
Vol 368-370 ◽  
pp. 1112-1117
Author(s):  
Jin Hui Li ◽  
Liu Qing Tu ◽  
Ke Xin Liu ◽  
Yun Pang Jiao ◽  
Ming Qing Qin
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Mechanical Performance ◽  
Chloride Ion ◽  
Limestone Powder ◽  
Ion Permeability ◽  
High Quality ◽  
Cracking Resistance ◽  
Slag Powder ◽  
Marine Concrete

In order to solve the environment pollution of limestone powder during production of limestone manufactured sand and gravel and problem of lack of high quality fly ash or slag powder in ocean engineering, ultra-fine limestone powder was selected for preparation of green high-performance marine concrete containing fly ash and limestone powder and that containing slag powder and limestone powder for tests on workability, mechanical performance, thermal performance, shrinkage, and resistance to cracking and chloride ion permeability. And comparison was made between such green high-performance concrete and conventional marine concrete containing fly ash and slag powder. Moreover, the mechanism of green high-performance marine concrete was preliminary studied. Results showed that ultra-fine limestone powder with average particle size around 10μm had significant water reducing function and could improve early strength of concrete. C50 high-performance marine concrete prepared with 30% fly ash and 20% limestone powder or with 30% slag powder and 30% limestone powder required water less than 130kg/m3, and showed excellent workability with 28d compressive strength above 60MPa, 56d dry shrinkage rate below 300με, cracking resistance of grade V, 56d chloride ion diffusion coefficient not exceeding 2.5×10-12m2/s. Mechanical performance and resistance to chloride ion permeability of limestone powder marine concrete were quite equivalent to those of conventional marine concrete. But it had better workability, volume stability and cracking resistance. Moreover, it can serve as a solution to the lack of high quality fly ash and slag powder.

Durability of Self-Compacting Concrete

2011 ◽  
Vol 324 ◽  
pp. 340-343
Author(s):  
Abdelaziz Benmarce ◽  
Hocine Boudjehem ◽  
Robila Bendjhaiche
Keyword(s):  
Oxygen Permeability ◽  
Chloride Ion ◽  
Chemical Characteristics ◽  
Capillary Absorption ◽  
Ion Diffusion ◽  
Self Compacting Concrete ◽  
Fresh State ◽  
Physical And Chemical ◽  
Transfer Properties ◽  
Chloride Ion Diffusion

Abstract. Self compacting concrete (SCC) seem to be a very promising materials for construction thanks to their properties in a fresh state. Studying of the influence of the parameters of specific designed mixes to their mechanical, physical and chemical characteristics in a state hardened is an important stage so that it can be useful for new-to-the-field researchers and designers (worldwide) beginning studies and work involving self compacting concrete. The objective of this research is to study the durability of self compacting concrete. The durability of concrete depends very much on the porosity; the latter determines the intensity of interactions with aggressive agents. The pores inside of concrete facilitate the process of damage, which began generally on the surface. We are interested to measure the porosity of concrete on five SCC with different compositions (w/c, additives) and vibrated concrete to highlight the influence of the latter on the porosity, thereafter on the compressive strength and the transfer properties (oxygen permeability, chloride ion diffusion, capillary absorption).

scholarly journals Transport Properties and Resistance Improvement of Ultra-High Performance Concrete (UHPC) after Exposure to Elevated Temperatures

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 416
Author(s):  
Yunfeng Qian ◽  
Dingyi Yang ◽  
Yanghao Xia ◽  
Han Gao ◽  
Zhiming Ma
Keyword(s):  
Compressive Strength ◽  
Transport Properties ◽  
High Temperatures ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Capillary Absorption ◽  
Self Healing

Ultra-high performance concrete (UHPC) has a high self-healing capacity and is prone to bursting after exposure to high temperatures due to its characteristics. This work evaluates the damage and improvement of UHPC with coarse aggregates through mechanical properties (compressive strength and ultrasonic pulse velocity), transport properties (water absorption and a chloride diffusion test), and micro-properties such as X-ray diffraction (XRD), Mercury intrusion porosimetry (MIP), and Scanning electronic microscopy (SEM). The result demonstrates that polypropylene (PP) fibers are more suitable for high temperature tests than polyacrylonitrile (PAN) fibers. The result shows that 400 °C is the critical temperature point. With the increase in temperature, the hydration becomes significant, and the internal material phase changes accordingly. Although the total pore volume increased, the percentage of various types of pores was optimized within 400 °C. The mass loss gradually increased and the ultrasonic pulse velocity gradually decreased. While the compressive strength first increased and then decreased, and the increase occurred within 25–400 °C. As for the transport properties, the chloride migration coefficient and capillary absorption coefficient both increased dramatically due to the higher sensitivity to temperature changes. The results of the property improvement test showed that at temperatures above 800 °C, the compressive strength recovered by more than 65% and the ultrasonic pulse velocity recovered by more than 75%. In terms of transport properties, compared to the results before self-healing, the chloride migration coefficient decreased by up to 59%, compared with 89% for the capillary absorption coefficient, after self-healing at 800 °C. With respect to the enhancement effect after exposure to high temperatures, the environment of a 5% Na2SO4 solution was not as good as the clean water environment. The corresponding changes in microstructure during the high temperatures and the self-healing process can explain the change in the pattern of macroscopic properties more precisely.

Effective Utilization of Industrial and Agricultural Waste for Developing Sustainable Self-Compacting Concrete

2022 ◽  
Vol 1048 ◽  
pp. 376-386
Author(s):  
M.S. Riyana ◽  
Dhanya Sathyan ◽  
M.K. Haridharan
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Portland Cement ◽  
Rice Husk ◽  
Ordinary Portland Cement ◽  
Rice Husk Ash ◽  
Cement Content ◽  
Supplementary Cementitious Materials ◽  
Ternary Blend ◽  
Self Compacting Concrete

SCC (Self compacting concrete) can fill formwork and encloses reinforcing bars under gravity and maintains homogeneity without vibration. SCC shortens the period of construction, guarantees compaction in confined zones, moreover terminates noise due to vibration. The wide spread application of SCC is restricted because of the high cost for the production of SCC with high cement content and chemical admixtures. In order to make the production of SCC economical, and to reduce the high cement content the Ordinary Portland Cement in SCC can be blended with pozzolanic materials like rice husk ash and supplementary cementitious materials like fly ash. In this paper the fresh state properties and mechanical properties such as compressive strength, split tensile strength and flexural strength of SCC with ternary blends of rice husk ash (RHA) and fly ash (FA) were studied. For this purpose, different mixes were prepared by replacing Ordinary Portland Cement (OPC) with 5%, 10%, 15% and 20% of rice husk ash (RHA) and the percentage of addition of fly ash (FA) is fixed as 15% for all these mixes. It was observed that the specimen incorporating 10% of rice husk ash (RHA) and 15% of fly ash (FA) as ternary blend exhibits better mechanical properties such as: Compressive, split tensile and flexural strengths at 28 days of age as compared to traditional mix of SCC without RHA (Rice Husk Ash) and FA (Fly Ash). This research demonstrates that the ideal percentage for a mixture of rice husk ash (RHA) and fly ash as ternary blend is 10% and 15% respectively.

scholarly journals Transport properties of self compacting concrete with limestone filler or fly ash

2006 ◽  
Vol 40 (5) ◽  
pp. 507-516 ◽  
Author(s):  
V. Boel ◽  
K. Audenaert ◽  
G. De Schutter ◽  
G. Heirman ◽  
L. Vandewalle ◽  
...  
Keyword(s):  
Fly Ash ◽  
Transport Properties ◽  
Self Compacting Concrete ◽  
Limestone Filler
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