Micromechanical analysis of self compacting concrete

A Comparative Study for the Prediction of the Compressive Strength of Self-Compacting Concrete Modified with Fly Ash

“…The collected SCC database taken from published literature [ 17 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ] includes information on the water–binder ratio, fly ash, fine and coarse aggregate, superplasticizer, and cement content (see Appendix A ). Each model performance is governed by the distribution of its parameters [ 61 ].…”

Micro X-ray computed tomography image-based two-scale homogenisation of ultra high performance fibre reinforced concrete

“…The averaged elastic moduli are E 11 =75.77GPa, E 22 =56.57GPa and E 33 =56.56GPa. E 11 is about 34% higher than E 22 and E 33 and the anisotropy ratio for all the models is about 0.70, suggesting that the material is no longer isotropic. E 11 =75.77GPa is about 28% higher than E H =59.02GPa of the 9mm RVE models with the same f f but randomly oriented fibres.…”

“…Fig .8b shows that some indentation marks touched the steel fibres and their measurements were discarded.The load vs. penetration depth curves for each indent was recorded and used to calculate the elastic moduli using the Oliver and Pharr method[48].Fig .9shows some examples for 1 N peak force.Figs .10a and bshow the frequency histogram of the elastic moduli for the silica sand and the cement paste, respectively. The mean and the standard deviation are 88.61 and 14.46 GPa for the silica sand, compared with 70.00 to76.30 GPa and 13.00-15.10 GPa for quartz sand in the literature measured by nano-indentation[23,24] and micro-indentation[22]. The obtained mean and standard deviation of elastic moduli for the cement paste is 58.33 GPa and 14.21 GPa, respectively, compared with much lower elastic moduli for normal cement paste, e.g.,22.80 GPa for w/c=0.5[19].a) In a sand particle (different peak loads) b) In the cement paste (peak force 0.3N) Micro-indentation marks Fig .9 Load-depth curve for cement and sand for peak force 1N.…”

“…The mean and the standard deviation are 88.61 and 14.46 GPa for the silica sand, compared with 70.00 to76.30 GPa and 13.00-15.10 GPa for quartz sand in the literature measured by nano-indentation[23,24] and micro-indentation[22]. The obtained mean and standard deviation of elastic moduli for the cement paste is 58.33 GPa and 14.21 GPa, respectively, compared with much lower elastic moduli for normal cement paste, e.g.,22.80 GPa for w/c=0.5[19].a) In a sand particle (different peak loads) b) In the cement paste (peak force 0.3N) Micro-indentation marks Fig .9 Load-depth curve for cement and sand for peak force 1N. a) cement paste b) silica sand Fig .10 Histograms of the micro-indentation measurements…”

“…In recent years, having recognised that the mechanical properties of cementitious composites at macro-scale are highly dependent upon the nano/micro-structures and respective properties of individual constituents, researchers have made considerable efforts in developing multiscale models using the above analytical homogenisation techniques (mainly Mori-Tanaka scheme), in which the results obtained at small scale are up-scaled to predict the behaviour at larger scales. For example, multiscale models for estimation of elastic properties have been built for cement paste [19,20], mortar and concrete [21][22][23] and UHPFRC [24].…”