Characterization of surface hardness and microstructure of high performance concrete

Abstract

The relationship between compressive strength obtained by universal testing machine and rebound value obtained by the hammer of high performance concrete was systematically investigated at the macro level. And a model of high performance concrete strength curve was established from them. At the micro level, the microstructure, hydration products and pore structure of concrete surface were analyzed by scanning electron microscopy (SEM), comprehensive thermal analysis (TG-DSC) and mercury intrusion porosimetry (MIP), respectively. The effect of carbonation on surface strength was also investigated. The results showed that the concrete surface hardness layer grew rapidly at early stage and then stabilized at last with ongoing curing age; the rebound value and compressive strength of concrete with slag were higher than those of concrete with the same content of fly ash. In addition, the strength curve obtained by the least square method can satisfy the local standard requirements with an average relative error of 8.9% and a relative standard deviation of 11.3%. When the carbonation depth was 6 mm, the compressive strength calculated by national uniform strength curve was 25 PMa higher than that by high performance concrete.

Keywords

high performance concrete / rebound test / parameter analysis / strength curve

References

[1] McCann DM, Forde MC. Review of NDT Methods in the Assessment of Concrete and Masonry Structures[J]. NDT & E International, 2001, 34(2): 71-84.

[2] Katalin S, Adorján B, István Zsigovics. Rebound Surface Hardness of Concrete: Introduction of an Empirical Constitutive Model[J]. Construction and Building Materials, 2011, 25(5): 2480-2487.

[3] Scrivener K. Impact of Microstructure on the Durability of Concrete[C]. 2th International Conference on Microstructural-related Durability of Cementitious Composites, 2008

[4] Katalin S, Adorján B, István Zsigovics. Extensive Statistical Analysis of the Variability of Concrete Rebound Hardness Based on a Large Database of 60 years Experience[J]. Construction and Building Materials, 2014, 53: 333-347.

[5] Demirhag S, Yavuz H. The Effect of Sample Size on Schmidt Rebound Hardness Value of Rocks[J]. International Journal of Rock Mechanics & Mining Sciences, 2009, 46: 725-730.

[6] Basu A, Aydin A. A Method for Normalization of Schmidt Hammer Rebound Values[J]. International Journal of Rock Mechanics & Mining Sciences, 2004, 41: 1211-1214.

[7] David F V, Will McDowall. The Foundations of the Environmental Rebound Effect and Its Contribution Towards a General Framework[J]. Ecological Economics, 2016, 125: 60-69.

[8] Breysse D. Nondestructive Evaluation of Concrete Strength: An Historical Review and a New Perspective by Combining NDT Methods[J]. Construction and Building Materials, 2012, 33: 139-163.

[9] Ha T L, Matthias M, Karsten Siewert. The Mix Design for Self-compacting High Performance Concrete Containing Various Mineral Admixtures[J]. Materials and Design, 2015, 72: 51-62.

[10] Lu J, Guan H, Zhao Weixuan. Compressive Strength and Permeability of High-performance Concrete[J]. J. of Wuhan University of Technology-Materials Science Edition, 2011, 1: 137-141.

[11] Carlos A G-G, Ana H, Julio F, et al. Porosity and Water Permeability Study of Supercritically Carbonated Cement Pastes Involving Mineral Addition[J]. Industrial & Engineering Chemistry Research, 2007, 46(8): 2488-2496.

[12] Pihlajavaara S E. Some Results of the Effect of Carbonation on the Porosity and Pore Size Distribution of Cement Paste[J]. Materials and Structure, 1968, 1(6): 521-526.

[13] Wan K, Xu Q, Wang Yudong. 3D Spatial Distribution of the Calcium Carbonate Caused by Carbonation of Cement Paste[J]. Cement & Concrete Composites, 2014, 45: 255-263.

[14] Saeki T, Ohga H, Nagataki S. Mechanism of Carbonation and Prediction of Carbonation Process of Concrete[J]. Concrete Library of JSCE, 1991, 17: 23-36.

[15] You L, Jiang L, Chu hongqiang. Influence of Carbonation on Fatigue of Concrete with High Volume of Ground Granulated Blast-furnace Slag[J]. J. of Wuhan University of Technology-Materials Science Edition, 2015, 2: 361-368.

[16] Sidney Diamond. Aspects of Concrete Porosity Revisited[J]. Cement and Concrete Research, 1999, 29(8): 1181-1188.

[17] Song H-W, Kwon S-Jun. Permeability Characteristics of Carbonated Concrete Considering Capillary Pore Structure[J]. Cement and Concrete Research, 2007, 37(6): 909-919.

[18] TA Bier. Influence of Type of Cement and Curing on Carbonation Progress and Pore Structure of Hardened Cement Pastes[C]. Materials Research Society Symposium Proceedings, 1986, 85(M): 123-134.

[19] Peter A C, Hanaa I Shaaban. Permeability and Pore Volume of Carbonated Concrete[J]. ACI Materials Journal, 1999, 96(3): 378-381.