Hybrid fiber reinforcement and crack formation in cementitious composite materials

The use of different types of fibers simultaneously for reinforcing cementitious matrices is motivated by the concept of a multi-scale nature of the crack propagation process. Fibers with different geometrical and mechanical properties are used to bridge cracks of different sizes from the micro- to the macroscale. In this study, the performance of different fiber reinforced cementitious composites is assessed in terms of their tensile stress-crack opening behavior. The results obtained from this investigation allow a direct quantitative comparison of the behavior obtained from the different fiber reinforcement systems. The research described in this paper shows that the multi-scale conception of cracking and the use of hybrid fiber reinforcements do not necessarily result in an improved tensile behavior of the composite. Particular material design requirements may nevertheless justify the use of hybrid fiber reinforcements.Fundação para a Ciência e a Tecnologia (FCT) - SFRH / BD / 36515 / 200

Analytical model for tensile strain hardening and Multiple cracking behavior of hybrid fiber-engineered cementitious composites

10.1061/(ASCE)0899-1561(2007)19:7(527)Journal of Materials in Civil Engineering197527-53

Flexural responses of hybrid steel-polyethylene fiber reinforced cement composites containing high volume fly ash

10.1016/j.conbuildmat.2006.01.002Construction and Building Materials2151088-1097CBUM

Review of potential structural applications of hybrid fiber Engineered Cementitious Composites

10.1016/j.conbuildmat.2012.04.010Construction and Building Materials36216-227CBUM

Fiber optic sensing for monitoring corrosion-induced damage

10.1177/1475921704042679Structural Health Monitoring32165-17

Strengthening of masonry walls using hybrid-fiber engineered cementitious composite

10.1177/0021998309346186Journal of Composite Materials4481007-1029JCOM

Effect of nano-clay on mechanical and thermal properties of geopolymer

The effect of nano-clay platelets (Cloisite 30B) on the mechanical and thermal properties of fly ash geopolymer has been investigated in this paper. The nano-clay platelets are added to reinforce the geopolymer at loadings of 1.0%, 2.0%, and 3.0% by weight. The phase composition and microstructure of geopolymer nano-composites are also investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) techniques. Results show that the mechanical properties of geopolymer nano-composites are improved due to addition of nano-clay. It is found that the addition of 2.0 wt% nano-clay decreases the porosity and increases the nano-composite's resistance to water absorption significantly. The optimum 2.0 wt% nano-clay addition exhibited the highest flexural and compressive strengths, flexural modulus and hardness. The microstructural analysis results indicate that the nano-clay behaves not only as a filler to improve the microstructure, but also as an activator to facilitate the geopolymeric reaction. The geopolymer nano-composite also exhibited better thermal stability than its counterpart pure geopolymer