Xianglong Su^*, Wenxiang Xu, Wen Chen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 77-77, 2019, DOI:10.32604/icces.2019.05090

Abstract Creep of concrete can last for decades, which displays the ultra-slow rheological phenomena. As an empirical formula, the logarithmic law is usually used to describe the ultra-slow creep. However, the logarithmic law does not always work well especially for the long-term creep. And its corresponding relaxation response cannot be obtained analytically. It is known that the Mittag-Leffler and the inverse Mittag-Leffler functions are generalized from the exponential and the logarithmic functions, respectively. And the inverse Mittag-Leffler function is much slower and generalized than the logarithmic function. In this paper, we use the non-local structural derivative to establish a new Maxwell-type… More >

Helen Hongniao Chen¹, Ray Kai Leung Su¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.15, No.3, pp. 91-102, 2010, DOI:10.3970/icces.2010.015.091

Abstract In this study, Electronic Speckle Pattern Interferometry (ESPI) technique was used to measure the surface displacement and strain fields around cracks in concrete beams. ESPI has high accuracy and can determine full-field deformations of concrete. However, tiny rigid-body movements of beam specimens can spoil the ESPI measurement and cause virtual deformations and false strains. Based on the theory of geometrical optics, this paper proposes a method to eliminate the false strains caused by rigid-body motion. The correction procedure was validated experimentally. Furthermore, the crack evolution in a pre-notched beam is presented. The critical minimum crack width of a microcrack is… More >

B.K.Raghu Prasad¹, Rabindra Kumar Saha¹, A.R.Gopalakrishnan¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.3, pp. 65-84, 2010, DOI:10.3970/icces.2010.014.065

Abstract Several different models have been proposed to characterize mode-I crack propagation in concrete. The fictitious crack model proposed by Hillerborg et al. and the blunt crack band theory developed by Bazant & Oh are particularly well suited for a finite element analysis. The two-parameter fracture model proposed by Jenq & Shah is found to be applicable only for beams with s/w=4, where s=span & w=depth of the beam. The general applicability of the model for other testing configurations is not published. In the present study an experimental verification of a one-parameter model based on fundamental equation of equilibrium developed by… More >

Z. Bittnar, L. Vrablik, M. Polak, V. Kristek¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.2, pp. 43-48, 2009, DOI:10.3970/icces.2009.013.043

Abstract Detail structural and dynamic analysis of concrete suspended bridge structure in Prague which was assessed because of severe damages of parapets and expansion joints is presented. Measured and calculated results are compared and approaches to repairing and stiffening are also recommended. More >

Eun A Hwang¹, Haeng-Ki Lee¹, Jong Won Kwark², Jung Woo Lee²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 11-12, 2009, DOI:10.3970/icces.2009.012.011

Abstract Concrete structures such as concrete safety barriers are often subjected to direct impact loads mainly due to vehicle crash impact. In this case, the impact resistance is one of the most critical characteristic of concrete used in such structures. The present study aims to characterize the impact resistance of lightweight aggregate cellular concrete (LACC), which will be used in concrete barriers. Impact tests on LACC specimens were carried out based on the repeated drop-weight impact test guideline recommend by ACI committee 544. Impact resistance and compressive strength of the LACC specimens were characterized and the results were used to determine… More >

Hisham Abdel-Fattah¹, Sameer Hamoush²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.4, pp. 111-112, 2009, DOI:10.3970/icces.2009.011.111

Abstract This paper develops Fiber Reinforced Plastic (FRP) Composites retrofit systems to enhance the structural performance of deficient reinforced concrete beams. The paper highlights the design of the different FRP systems and then, systems with promising results are used to upgrade deficient beams. Structural evaluation for retrofitted beams is performed to evaluate the ductility and strength performance. This study mainly focuses on the uses of Glass Fiber Reinforced Plastics (GFRP), Carbon Fiber Reinforced Plastics (CFRP) and hybrid reinforced plastics that use a mixture of carbon and glass fibers. As part of the design of the FRP systems, an experimental program was… More >

H. Cifuentes¹, F. Medina²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.7, No.4, pp. 197-202, 2008, DOI:10.3970/icces.2008.007.197

Abstract The most popular expression that considers the size effect showed in concrete structures is the size effect law of Bazant. This law depends on two coefficients G_f and c_f. For the experimental determination of these coefficients is necessary obtaining the ultimate loads, in three points bending tests, of notched beams with different sizes. In this work, a method to determine the coefficients about the results on identical beams varying the deep of the notch, is presented. The necessary values of loads are obtained by a numerical analysis with FEM that considers non linear behaviour of the concrete material. Next the… More >

B.K. Raghu Prasad¹, T.V.R.L. Rao¹, A.R.Gopalakrishnan¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.2, pp. 99-112, 2008, DOI:10.3970/icces.2008.006.099

Abstract A modified lattice model using finite element method has been developed to study the mode-I fracture analysis of heterogeneous materials like concrete. In this model, the truss members always join at points where aggregates are located which are modeled as plane stress triangular elements. The truss members are given the properties of cement mortar matrix randomly, so as to represent the randomness of strength in concrete. It is widely accepted that the fracture of concrete structures should not be based on strength criterion alone, but should be coupled with energy criterion. Here, by incorporating the strain softening through a parameter… More >

Roberta Apostolska¹, Golubka Necevska-Cvetanovska²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.2, pp. 129-136, 2008, DOI:10.3970/icces.2008.005.129

Abstract The IZIIS' contribution to development of high quality materials has been seen in realization of several scientific-research projects in the field of high strength concrete in the period from 1992 to 2006. Within the frames of these projects complex laboratory-experimental-analytical investigations have been performed to contribute to definition of the methodology for obtaining high stength concrete exclusively from domestic resources, to investigate joint behaviour of high strength materials and elements in nonlinear range as well as to define dynamic behaviour high strength concrete buildings exposed to seismic actions. The selected results from these investigations are presented in the paper. More >

Morgan Chabannes^1,2,*, Frédéric Becquart^1,2, Nor-Edine Abriak^1,2

Journal of Renewable Materials, Vol.7, No.9, pp. 855-863, 2019, DOI:10.32604/jrm.2019.06779

Abstract The return to old building methods by mixing crop by-products with mineral binders is arousing great interest in Europe since about 25 years. The use of these bio-aggregates based materials for the design of building envelopes is a valuable opportunity to deal with increasingly demanding thermal regulations. In addition, the regulatory framework is moving towards reducing the overall car-bon footprint of new buildings. Some traditional and historic buildings are based on timber framing with earth-straw as infill material for instance. Hemp concrete is a bio-based material that can be manually tamped in timber stud walls or more recently in the… More >