Influence of fly ash on early-age cracking behavior of high-flowing concrete

Abstract

The effects of quality and content of fly ash on the early-age cracking behavior of high-flowing concrete (HFC) were investigated. The early-age cracking behavior of the HFC was analyzed by combining the tests of evaporation capacity and electrical resistivity of the HFC. In these tests, a modified flat-type specimen was adopted. The results show that the HFC will have a lower evaporation capacity when it is mixed with fine fly ash, while it will have a higher evaporation capacity when grade III fly ash is used as mineral admixture. And the electrical resistivity rate of HFC reduces with the increase of the content of fly ash. A nonlinear relationship exists between the cracking time of HFC and the minimum electrical resistivity. The early-age cracking behavior of HFC with fly ash can be enhanced by appropriately increasing the fine particle content and MgO, K₂O, and SO₃ contents of fly ash. The optimal content of fly ash, which makes a satisfied early-age cracking behavior of HFC, is obtained. And when the content of fly ash exceeds a critical value, the early-age cracking behavior of HFC will rapidly decrease.

Keywords

high-flowing concrete / fly ash / cracking behavior / electrical resistivity

References

[1] BaH.-j., GaoX.-jian.. Restrained cracking tendency of HPC at early age [J]. Concrete, 2002, 151(5): 3-6

[2] RaghuprasadP. S., KumarA. V. P., NagendraR.. Chloride penetration and drying shrinkage studies on blended cement and OPC concrete with reference to marine environment [J]. Indian Concrete Journal, 2007, 81(2): 39-43

[3] SubramaniamK. V., GromotkaR., ShahS. P., OblaK., HillR.. Influence of ultrafine fly ash on the early age response and the shrinkage cracking potential of concrete [J]. Journal of Materials in Civil Engineering, 2005, 17(1): 45-53

[4] KumarB., TikeG. K., NandaP. K.. Evaluation of properties of high-volume fly-ash concrete for pavements [J]. Journal of Materials in Civil Engineering, 2007, 19(10): 906-911

[5] GaoY.-l., ZhouS.-qiong.. Influence of ultra-fine fly ash on hydration shrinkage of cement paste [J]. J Cent South Univ Technol, 2005, 12(5): 596-600

[6] AkkayaY., OuyangC. S., ShahS. P.. Effect of supplementary cementitious materials on shrinkage and crack development in concrete [J]. Cement and Concrete Composites, 2007, 29(2): 117-123

[7] LeeH. K., LeeK. M., KimB. G.. Autogenous shrinkage of high-performance concrete containing fly ash [J]. Magazine of Concrete Research, 2003, 55(6): 507-515

[8] ChindaprasirtaP., HomwuttiwongS., SirivivatnanonV.. Influence of fly ash fineness on strength, drying shrinkage and sulfate resistance of blended cement mortar [J]. Cement and Concrete Research, 2004, 34: 1087-1092

[9] LiX.-g., MaB.-g., WangX.-g., ZhuH.-bo.. Effect of fly ash on shrinkage and cracking of cement-based materials [J]. Concrete, 2005, 192(10): 38-43

[10] PengW.-b., HeZ., LiangW.-quan.. Effects and evaluation on cracking behavior of concrete [J]. Journal of Building Material, 2004, 17(3): 317-322

[11] WangJ.-c., YanP.-yu.. Analysis of Portland cement-fly ash composite binder drying crack [J]. Journal of Shenyang Jianzhu University: Natural Science, 2005, 21(5): 519-522

[12] QIAN Jue-shi, LI Chang-tai, TANG Zu-quan. The effect of mineral blenders on the electrical bulk resistivity of steel-slag concrete [J]. Fly Ash Comprehensive Utilization, 2004(4): 7–9. (in Chinese)

[13] LiZ.-j., XiaoL.-z., WeiX.-sheng.. Determination of concrete setting time using electrical resistivity measurement [J]. Journal of Materials in Civil Engineering, 2007, 19(5): 423-427

[14] JiangZ.-wu.Study on moisture diffusion and self shrinkage in high performance concrete [D], 2002, Shanghai, Tongji University

[15] WeiX.-sheng.Interpretation of hydration process of cement-based materials using electrical resistivity measurement [D], 2004, Hong Kong, Hong Kong University of Science and Technology

[16] DiasW. P. S.. Influence of mix and environment on plastic shrinkage cracking [J]. Magazine of Concrete Research, 2003, 55(4): 385-394

[17] GaoX.-j., BaH.-jing.. Characteristics of early age shrinkages development of HPC containing mineral admixtures [J]. Journal of Harbin Institute of Technology, 2004, 36(12): 1615-1618

[18] NelsonP., SrivivatnanonV., KhatriR.. Development of high volume fly ash concrete for pavements [C]. Proceedings of the 16th Australian Road Research Board Conference, 1993, Vermont, Australian Road Research Board: 37-47

[19] CengizD. A.. High-volume fly ash concrete with high strength and low drying shrinkage [J]. Journal of Materials in Civil Engineering, 2003, 15(2): 153-156

[20] TangtermsirikulS.. Effect of chemical composition and particle size of fly ash on autogenous shrinkage of paste [C]. Proceedings of an International Workshop on the Autogenous Shrinkage of Concrete, 1999, London, E &FN Spon: 175-185

[21] MirzaJ., MirzaM. S., RoyV., SalehK.. Basic rheological and mechanical properties of high-volume fly ash grouts [J]. Construction and Building Materials, 2002, 16: 353-363