CONCRETE STRENGTH PREDICTION IN STRUCTURAL ELEMENTS MADE WITH PULVERISED FUEL ASH

2007 ◽  
pp. 385-394
Author(s):  
A. Hatzitheodorou ◽  
M. N. Soutsos
Keyword(s):  
Concrete Strength ◽  
Strength Prediction ◽  
Structural Elements ◽  
Fuel Ash

scholarly journals Experimental research on concrete strength prediction by Limpet pull-off test in China

2014 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Can Chen ◽  
Weiliang Jin ◽  
Hangjie Ding ◽  
Yuxi Zhao ◽  
P.A. Muhammed Basheer ◽  
...  
Keyword(s):  
Experimental Research ◽  
Concrete Strength ◽  
Strength Prediction

The Effect of Eggshell Powder as an Accelerator for Blended Cement Concrete

2020 ◽  
Vol 17 (2) ◽  
pp. 1032-1036
Author(s):  
Nur Nadhira Abdul Rasid ◽  
Abdul Rahman Mohd. Sam ◽  
Azman Mohamed ◽  
Nor Hasanah Abdul Shukor Lim ◽  
Zaiton Abdul Majid ◽  
...  
Keyword(s):  
Calcium Oxide ◽  
Palm Oil ◽  
Concrete Strength ◽  
Strength Development ◽  
Early Age ◽  
Palm Oil Fuel Ash ◽  
Fuel Ash ◽  
Early Strength ◽  
Oil Fuel ◽  
Silica Oxide

Blended concrete has later strength development with long maturity strength development. An accelerator is thus needed to enhance the early strength development of concrete. This paper shows the combination of ground palm oil fuel ash and eggshell powder that was designed for later and early strength development, respectively. Two types of eggshell powder were utilised in concrete: uncarbonised eggshell powder and decarbonised eggshell powder. The study was initiated with compression test for concrete curing at age 1, 3, 7, and 28 days followed by rapid evaluation test of setting time to investigate the preliminary performance between materials. The results revealed decarbonised eggshell powder as a high accelerator that can improve the early age of concrete strength development. Meanwhile, despite showing the best performance, uncarbonised eggshell powder is a very low accelerator thus not fit the purpose. In conclusion, the combination of ground palm oil fuel ash (rich with silica oxide) and decarbonised eggshell powder (rich with calcium oxide) provided dual function, where ground palm oil fuel ash and decarbonised eggshell powder took later and early strength development, respectively. The combination between silica oxide and calcium oxide in cementitious materials has potential to be utilised to enhance the early age of a blended concrete strength development.

Effect of Tow Sheet Composite Wrap Architecture on Strengthening of Concrete Due to Confinement: I—Experimental Studies

1995 ◽  
Vol 14 (9) ◽  
pp. 1008-1030 ◽  
Author(s):  
Ian Howie ◽  
Vistasp M. Karbhari
Keyword(s):  
Concrete Strength ◽  
Experimental Studies ◽  
Load Carrying Capacity ◽  
Structural Elements ◽  
New Techniques ◽  
Column Type ◽  
Load Carrying ◽  
Concrete Shell ◽  
Original Construction ◽  
Stub Columns

Worldwide there is a need for the renewal of infrastructure because of age, deterioration, misuse, lack of timely repair and maintenance, use of improper materials and/or techniques in the original construction, and even changing needs. Notwithstanding the need for retrofit and repair methods for column-type structural elements, there is also a need for new techniques that would increase the confining action of concrete, as well as enhance the load-carrying capacity and ductility of such structures from a strengthening, rather than a seismic, viewpoint. This study investigates the use of carbon-fiber-reinforced jackets applied to concrete stub columns through the use of tow-sheet-type fabric forms. The primary emphasis is on the investigation of orientation and thickness effects of the composite wraps on the load-carrying efficiency and enhanced ductility of the new structural elements. It was seen that the predominant use of hoop reinforcement provides significant enhancement in concrete strength through confining action and also offers the potential for fabrication of concrete shell-type elements that would enable reinforcing action without the use of steel and the attending problems of corrosion.

scholarly journals Refined strength prediction of concrete 2D bottle-shaped struts

2021 ◽  
Vol 4 (2) ◽  
pp. 111-125
Author(s):  
Abdelrazek E. Ebrahim ◽  
Omar M. Elmeligy ◽  
Salah E. El-Metwally ◽  
Mashhour A. Ghoneim ◽  
Hamed S. Askar
Keyword(s):  
Concrete Strength ◽  
High Strength ◽  
Experimental Tests ◽  
Strength Prediction ◽  
Width Ratio ◽  
Element Analysis ◽  
Minimum Reinforcement ◽  
Strength Concrete ◽  
Bearing Plate ◽  
Effectiveness Factors

For better strength prediction using strut-and-tie models (STM), it is essential to use reliable strength parameters of the model components; e.g., struts, ties, and nodes. Among all the elements of the STM, the strength of the bottle-shaped struts is not well quantified. The purpose of this study is to develop more accurate formulas for the calculation of the effectiveness factors for 2D bottle-shaped struts, that are unreinforced, reinforced with minimum reinforcement, and reinforced with sufficient transverse reinforcement. The nonlinear finite element analysis, with the aid of the software ABAQUS, has been utilized in this study, which has been verified against experimental tests. The study has been carried out for grades of concrete varying from 20 to 100MPa, and for bearing plate to width ratio varying from 0.1 to 0.9. The obtained formulas for the effectiveness factors of bottle-shaped struts are functions of the concrete strength, which is not the case with the ACI 318-19 provisions. These formulas have been verified against experimental tests and have been compared with the ACI 318-19 provisions. The predictions based on these formulas are more accurate than those based on the ACI 318-19 provisions. Also, the results from these formulas are always on the safe side. On the other hand, the ACI 318-19 provisions lead to unsafe results in the case of high-strength concrete and very conservative results for the case of unreinforced struts from normal-strength concrete.

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