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We have described the synthesis of composite materials with different titanium dioxide loading on hydroxyapatite (TiO2/HAp). Their structural properties and morphologies were established by powder X‐ray diffraction (p‐XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM) and Fourier transform infrared (FT‐IR) analyses. The catalytic efficacy of the as‐prepared composite materials was explored to synthesise novel 4‐oxo‐chromen‐dihydropyridine derivatives by the four‐component reaction. The one‐pot fusion in ethanol medium involved chromene‐3‐carbaldehyde, dimethyl acetylenedicarboxylate, malononitrile and different aromatic and heteroaryl amines. The method provided impressive yields (92–97%) of the target products in a short reaction time (<21 min) at room temperature. Further, we examined the efficiency of the separated catalyst, reused up to five runs with similar catalytic activity. This sustainable protocol merits easy workup, fast reaction time, superior yields, catalyst reusability, mild reaction environment and column‐free purification.

Concrete’s thermal properties are more complex than for most materials because not only is the concrete a composite material whose constituents have different properties, but its properties also depend on moisture and porosity. Exposure of concrete to elevated temperature affects its mechanical and physical properties. In the current study, M40 and M80 grades of plain self-compacting concrete (SCC) mixes are developed using Nan Su mix design principles to investigate the effect of elevated temperatures on 1) weight and compressive strength 2) compressive strength of SCC when tested cool and hot 3) effect of 2, 4 and 6 hrs. exposure duration of elevated temperatures on compressive strength 4) modulus of elasticity 5) size of testing specimen and 5) effect of thermal cycles on SCC mixes. Results derived the following conclusions 1) the M80 specimens lose more strength than M40 SCC specimens when subjected to elevated temperatures ;2) specimens heated and then permitted to cool before testing lose more strength than those tested while hot; 3) the longer the duration of heating before testing, the larger the loss in strength; 4) The decrease in modulus of elasticity caused by elevated-temperature exposure is more pronounced than the decrease in compressive strength. 5) Small test specimens generally incur greater strength losses than larger ones and 6) Specimens subjected to several cycles of heating and cooling lose more strength than those not subjected to thermal cycling.