Evaluating the distance between particles in fresh cement paste based on the yield stress and particle size

• Published in: Construction & building materials Vol. 142; pp. 109 - 116
• Main Authors: Guo, Yiqun, Zhang, Tongsheng, Wei, Jiangxiong, Yu, Qijun, Ouyang, Shixi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2017; Elsevier B.V
• Subjects: Analysis; Cements (Building materials); Distance between particles; Fresh cement paste; Mechanical properties; Particle size; Solid volume concentration; Stresses (Materials); Yield stress; China; Distance between particles; Particle size; Solid volume concentration; Yield stress; Fresh cement paste
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2017.03.055

[Display omitted] •The coarser particles needed larger λ to achieve same yield stress of paste.•The relationships between yield stress and λ were established.•λ in binary-cement pastes was evaluated in consideration of particle size.•Reliability of the evaluation of λ was validated experimentally.•This paper gives a deeper insight into initial packing and bridging of particles. The distance between particles (λ) plays a key role in the flowability of fresh cement pastes. λ given in available literatures is an average value and independent with the particle size. Actually, coarse particles in cement paste need a larger λ to achieve same yield stress compared with fine particles. In the present study, relationship between yield stress and λ for single-fraction cement pastes was established by introducing an exponential-type function. Then the function was theoretically deduced to evaluate λ in binary-fraction cement pastes. For cement pastes with yield stress of 30Pa, distance between coarse particle (48.51μm) and fine particle (6.63μm) was 5.00μm, while distance between mid-sized particle (20.27μm) and fine particle (6.63μm) was only 2.57μm. Finally, the reliability of λ in binary-fraction cement paste was experimentally validated. This method can be applied in multi-fraction cement pastes, and λ in consideration of particle size will give a deeper insight in the flowability and microstructural development of cement pastes.