Estimating long-term creep and shrinkage of high-strength concrete

2008 ◽  
Vol 30 (4) ◽  
pp. 316-326 ◽  
Author(s):  
M. Mazloom
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Term Creep ◽  
Creep And Shrinkage

Research on Creep Performance of C60 High Performance Concrete

2009 ◽  
Vol 405-406 ◽  
pp. 400-404
Author(s):  
Jian Yin ◽  
Yi Jin Li ◽  
Ke Ren Zheng ◽  
Shi Dong Luo ◽  
Ai Guo Yan ◽  
...  
Keyword(s):  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Railway Bridge ◽  
Engineering Construction ◽  
Strength Concrete ◽  
Creep Coefficient ◽  
Term Creep

It was tested creep performance of C60 high strength concrete and C60 HPC to calculate the long-term creep of C60 HPC accurately, which was combined with engineering construction of Yichang Chang Jiang Railway Bridge. It was concluded the creep degree and creep coefficient of C60 HPC by means of optimization fit calculation, which gives scientific foundation for the design and construction of this bridge.

Characteristics of Treated Palm Oil Fuel Ash and its Effects on Properties of High Strength Concrete

2012 ◽  
Vol 626 ◽  
pp. 152-156 ◽  
Author(s):  
A.M. Zeyad ◽  
M.A. Megat Johari ◽  
Norazura Muhamad Bunnori ◽  
K.S. Ariffin ◽  
Nurdeen M. Altwair
Keyword(s):  
Palm Oil ◽  
High Strength Concrete ◽  
High Strength ◽  
Ash Content ◽  
Unburned Carbon ◽  
Palm Oil Fuel Ash ◽  
Strength Concrete ◽  
Fuel Ash ◽  
Oil Fuel

Palm oil fuel ash obtained from palm oil mill was treated via screening, grinding and heating to improve its pozzolanic reactivity. The characteristics of the palm oil fuel ash before and after treatment were monitored to assess the changes in the properties of the palm oil fuel ash. The resulting ultrafine palm oil fuel ash was then utilized to produce high strength concrete by replacing the ordinary Portland cement at 0, 20, 40 and 60% on mass-for-mass basis. The results show that the treatment process undertaken reduces the particle size, diminishes the unburned carbon content, while at the same time increases the glassy phases. The utilization of the ultrafine palm oil fuel ash in high strength concrete was observed to improve workability especially at higher ultrafine palm oil fuel ash content. In addition, the long-term compressive strength of the high strength concrete was significantly increased with the ultrafine palm oil fuel ash inclusion. Further, the long-term rapid chloride permeability was significant reduced especially at higher ultrafine palm oil fuel ash content of 60%, which could be translated into superior durability performance.

Creep, shrinkage, frost, and sulphate resistance of high strength concrete

1995 ◽  
Vol 22 (3) ◽  
pp. 621-636 ◽  
Author(s):  
Sujit Ghosh ◽  
K. W. Nasser
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Frost Resistance ◽  
High Strength Concrete ◽  
High Strength ◽  
Air Entrainment ◽  
Strength Concrete ◽  
Binder Ratio ◽  
Matrix Morphology ◽  
Creep And Shrinkage

A comprehensive study was undertaken to determine the shrinkage, creep, and durability of high strength concrete (50–70 MPa) containing silica fume and lignite fly ash. The concrete mixtures contained normal CSA type 10 (ASTM type 1) portland cement, 10% condensed silica fume, and different amounts of fly ash that varied between 0 and 80% of the weight of binder in the mixture. The aggregates-to-binder ratio by weight was maintained at 5 and the weight of the superplasticizer was varied between 1.5% and 2.2% of the binder while the water-to-binder ratio was maintained at 0.27. The test program consisted of compressive strength tests at various ages on concrete cylinders; drying shrinkage tests at room temperature; creep tests of sealed and unsealed concrete at room temperature (21 °C (70°F)) and at high temperatures (up to 232 °C (450°F)) under three different stress regimes; frost resistance tests on concrete prisms up to 300 freezing and thawing cycles; and sulphate resistance tests on concrete prisms immersed in 5% Na2SO4 solution for up to 10 months. The results indicated that up to 60% fly ash replacement with 10% silica fume showed either superior or similar 28- and 56-day compressive strengths when compared with the 100% cement control mixture. Fly ash + silica fume concrete indicated lower shrinkage and long-term creep. Creep increased with increase in temperature due to physico-chemical processes, which were confirmed by microstructure analysis using the scanning electron microscope. The creep and shrinkage data of high fly ash + silica fume concrete fitted well to the current ACI creep and shrinkage model. Replacement of cement by up to 35% fly ash and 10% silica fume indicated enhanced frost resistance, without any air-entrainment. The addition of 8% air-entrainment to the 20% fly ash + 10% silica fume mixture increased the durability factor by about 10%. For the 50% fly ash + 10% silica fume mixture, the frost durability factor was found comparable to that of the 100% cement control mixture, and air entrainment did not improve its value appreciably. Sulphate resistance of concrete made with 100% CSA type 10 cement was found satisfactory; however, with increasing fly ash contents (up to 50%), the expansion due to sulphate action was suppressed. A study of matrix morphology and microstructure bonding, using the scanning electron microscope, helped to explain the observed results in a comprehensive manner. Key words: creep, shrinkage, compressive strength, frost resistance, durability factor, sulphate resistance, fly ash, silica fume, high-strength concrete, SEM micrograph, matrix morphology.

scholarly journals Long Term Stability and Microstructure of Steam Cured High Strength Concrete with Ettringite Based Additives.

1995 ◽  
Vol 44 (502) ◽  
pp. 967-972
Author(s):  
Hiroshi MUGURUMA ◽  
Yoshihisa MATSUNAGA ◽  
Yoshiharu WATANABE ◽  
Etsuo SAKAI
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Term Stability ◽  
Long Term Stability
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