Research on the Chloride-free and Alkali-free Liquid Set Accelerator for Sprayed Concrete

Author(s): Ling WANG, Jiezhong GAN, Xia ZHAO, Ping ZHANG and Yading Xu
Paper category: Proceedings
Book title: Proceedings of International Conferences (ICACMS) Advances in Construction Materials and systems Vol 2
Editor(s): Manu Santhanam, Ravindra Gettu, Radhakrishna G. Pillai, Sunitha K. Nayar
ISBN: 978-2-35158-194-0
e-ISBN: 978-2-35158-191-9
Publisher: RILEM Publications SARL
Publication year: 2017
Pages: 236-245
Total Pages: 10
Language : English

Abstract: Sprayed concrete is used for the construction of tunnel and mine. The recent trend in accelerator development is the chloride-free and alkali-free liquid accelerator in response to the demand for durable, high-quality sprayed concrete that minimizes environmental risk. A kind of liquid accelerator characterized of environmental friendly, chloride-free and alkali-free (named ASA) is developed through orthogonal experiments. Relevant properties and action mechanism of the accelerator were studied. When the dosage of ASA accelerator is 7%, the initial and final setting time of cement paste were decreased to 2min40s and 4min40s respectively. The 1d compressive strength and 28d compressive strength of concrete with ASA increased by 43.5% and 10.2% respectively. XRD, ESEM and MIP were used to analysis the hydration products and microstructure of hardened cement paste with ASA. It shows that the fast setting and high early compressive strength of cement paste with ASA are due to Al3+ and SO4 2- in ASA reacted with dissolved Ca2+ in the liquid phase instantly forming a large amount of ettringites. The consumption of Ca2+ in liquid phase promoted the hydration of C3S, the generated C-S-H gel filled in the pore, making the microstructure denser and increasing the 28d compressive strength.

Online publication : 2017
Publication type : full_text
Public price (Euros) : 0.00

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