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Though previous studies have indicated that the fresh behaviours of plain mortar/concrete are mainly governed by the average water film thickness (AWFT), whether the concept of AWFT is also applicable to fibrous mortar/concrete still needs to be explored. Furthermore, for fibrous mortar/concrete, it is obvious that the fibres added also have certain effects on the fresh behaviours. In two previous studies on basalt fibre-reinforced mortar (BFRM), the integral effects of the AWFT and fibre dosage as well as the integral effects of the AWFT and fibre length were individually investigated. In this study, a fibre factor (FF) defined as the fibre volume multiplied by the fibre aspect ratio was employed and 24 extra mortar groups were tested. A total of 68 mortar groups were applied in numerical analysis. The results of the regression analysis yielded good correlations of the workability, fluidity, cohesiveness, and adhesiveness of BFRM with the AWFT and FF, suggesting that the AWFT and FF are together the governing parameters controlling the fresh behaviours of BFRM. Hence, the AWFT and FF may be used to develop a model for the fresh properties of BFRM. [ABSTRACT FROM AUTHOR]

• Micro Fe 3 O 4 and nano Fe 3 O 4 used together to produce EM wave absorbing mortar. • Adding micro and/or nano Fe 3 O 4 improved strength, packing and microstructure. • Co-addition of micro and nano Fe 3 O 4 has additive effect on EM wave absorption. Fe 3 O 4 (ferroferric oxide) has been proven to be useful for enhancing the electromagnetic (EM) wave absorption performance of cementitious materials. However, there are still few studies on the possible combined usage of micro Fe 3 O 4 and nano Fe 3 O 4 to further enhance the EM wave absorption performance and perhaps also the other performance attributes of cementitious materials. In this research, an attempt to utilize both micro Fe 3 O 4 and nano Fe 3 O 4 to produce EM wave absorbing mortar was made. A series of mortar mixes with varying amounts of micro Fe 3 O 4 and nano Fe 3 O 4 added were tested to investigate their combined effects on the workability, compressive strength, packing density, microstructure and EM wave absorbing properties. The results showed that the combined addition of micro and nano Fe 3 O 4 had little net effect on the workability, but significant positive effects on the compressive strength, packing density and microstructure densification, and more importantly, such combined addition could increase the EM wave absorption performance to higher than possible with only single addition of micro Fe 3 O 4 or nano Fe 3 O 4. [ABSTRACT FROM AUTHOR]