During the recent years, the use of pozzolanic materials (e.g. volcanic ash) in concrete and cement manufacturing has increased significantly since it can reduce the environment hazard associated with using Portland cement. In this paper, the effect of elevated temperatures on the physical and mechanical characteristics of building mortar produced with volcanic ash is experimentally explored. In order to evaluate the performance of the mortar, four different proportions of volcanic ash (0, 5, 15 and 25%)-as weight replacement of the cement-were prepared. A series of tests were conducted after 28, 90 and 120 days under different temperatures (25, 200, 500 and 800Cº). This paper demonstrates that the replacement of cement by a proportion of volcanic ash can sustain an acceptable level of compressive strength and improve the overall characterization of the mortar while reducing the amount of CO2 released. The mortar with 15% ratio of the volcanic ash replacement showed better flexural and the tensile strength. This paper also heights that the volcanic ash replacement affects the late-age properties of the mortar more than the early-age ones at both ambient and elevated temperatures.

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For reinforced concrete members subjected to high temperature, the degree of in-service loading, commonly expressed as the loading ratio, can be highly influential on the structural behaviour. In particular, the loading ratio may be pivotal in relation to the phenomenon of load-induced thermal strain. Despite its potentially pivotal role, to date, the influence of the loading ratio on both material and structural behaviour has not been explored in detail. In practice, real structures experience variation in imposed loading during their service life and it is important to understand the likely response at elevated temperatures across the loading envelope. In this paper, the effect of the loading ratio is numerically investigated at both material and structural level using a validated finite element model.The model incorporates a proposed constitutive model accounting for load-induced thermal strain and this is shown to outperform the existing Eurocode 2 model in terms of accuracy. Using the validated model, the specific case of flats slabs and the associated connections to supporting columns at various loading ratios are explored. For the cases examined, a marked difference in the structural behaviour including displacement direction was captured from low to high loading ratios consistent with experimental observations.

Surrogate models to predict maximum dry unit weight, optimum moisture content and California bearing ratio form grain size distribution curve '. Road Materials and Pavement Design, 23(12).

The important component in the asphalt mixture is mineral filler materials as it plays an essential part in the stiffening and toughening of asphalt binder. In addition, the mechanical properties of asphalt binder are influenced by the mineral filler, and significantly affected with respect to stripping or moisture susceptibility. This paper is displayed the mechanical properties of asphalt mixtures that used asphalt binder grade (40-50), the gradation of aggregates selected with the mid-point according to the Iraqi specification and two types of mineral filler materials (High Reactivity Attapulgite (HRA) and Portland Cement (PC)) according to the empirical requirements. The mixtures are produced and compacted according to the Marshall Mix design method. In addition, this paper is displayed the positive influence of HRA and PC in the asphalt mixtures such as (Volumetric Properties, Marshall Properties, Marshall Stiffness, the Indirect Tensile Strength and Moisture Susceptibility). The results explained that the (5%) and (7%) HRA had an important influence on the properties of asphalt mixtures. With the increment in the percentages of HRA, the volumetric properties of asphalt mixtures enhanced. Laboratory investigation results support the advantage of adding HRA to the asphalt mixtures. HRA as an active mineral filler has good resistance to moisture sensitivity and mechanical properties, which contributes to extending the life cycle of the pavement layer.