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Changes in materials'' physical, chemical and mechanical properties have to be known to decide whether the buildings exposed to high-temperature effect will be repaired or demolished. In order to carry out the effects of fire and extinguishing on the properties of concrete, mortars with and without silica fume were exposed to different temperatures, such as 100, 200, 300, 600, 900 and 1200 °C, and cooled slowly in the air and fast in water in two groups. Flexural and compressive-strength tests were performed on the samples which were cooled up to room temperature and changes in color were determined by using the Munsell Color System. High temperature has caused damages in mechanical properties of mortars with or without silica fume, especially samples which were cooled in water, which showed significant decrease in mechanical strengths at 600 °C. In this study, it was observed that the changes in color''s hue component and the compressive strength have similarities. Test results show that residual color changes in mortar can give an idea about the effect of high temperatures on the mechanical properties of mortar during a fire. [Copyright &y& Elsevier]

Abstract: The aim of total quality management (TQM) is to offer satisfactorily high quality products to customers for providing increased productivity and decreased costs. Various methods are used for process improvement, development and optimization. In ready mixed concrete production, the number and the variations of effect parameters can be reduced using response surface methodology. In this study, firstly influence levels of the main and interaction terms of effect variables were determined using 27–3 fractional factorial design in order to reduce the number of simultaneously controllable variables. Then, quadratic terms were determined using D-Optimal design, and response surface graphics were plotted. [Copyright &y& Elsevier]

calcium carbonate at 950℃ and 1100℃. The sample calcined at 1100℃ was subjected to mechanical grinding since it was found suitable for injection grout production according to its mineralogical and chemical composition and its cementation and hydraulic index values obtained by XRD and XRF analyses. Grain sizes of the ground sample and a common commercial grout material were determined by DLS analysis. The comparison following XRF and DLS analyses revealed that the ground sample has smaller grains in the nanometer range and higher cementation and hydraulic index values than the commercial product. Various grouts were prepared with the addition of water and chemical admixture to the ground sample in different ratios. Fluidity, volume stability and penetration properties of the grouts were evaluated according to Marsh Funnel, Flow Cone, bleeding, and sand column tests, respectively. The limit requirements of these tests were achieved with the selected water to binder ratio, chemical admixture amount and mixing procedure. Moreover, bending and compression tests were performed on the hardened grouts on the 28th and 90th days. The grout prepared with selected proportions and mixing procedure showed higher flexural and compressive strength on the 90th day than the commercial one. Based on these results, it has been concluded that the new grout can be an alternative to existing commercial products used for the consolidation of historic buildings. [ABSTRACT FROM AUTHOR]

Utilization of the struvite recovered from sheep slaughterhouse wastewater was explored for the first time in sustainable cement production and fire-resistant wooden structure design. Sheep abattoir-originated struvite precipitation process was optimized using a chemical combination of MgCl 2.6H 2 O + NaH 2 PO 4.2H 2 O, a molar ratio of Mg2+:NH 4 +-N:PO 4 3--P = 1.2:1:1, a reaction pH of 9.0, an initial ammonium concentration of 240 mg NH 4 +-N/L, and a reaction time of 15 min. Based on both American (ASTM C305-14) and Turkish (TS EN 196–1) standard methods, struvite was used in proportions of 10–30% by weight for struvite-substituted cement production. The best compressive strength values were achieved with 85.5% cement clinker (C), 4.5% gypsum (G), and 10% struvite (S) for the struvite-replaced cement (C85.5G4.5S10). According to the US EPA's greenhouse gas protocol, it was estimated that producing 10% struvite-substituted cement would result in 9.97% lower absolute CO 2 emissions than producing 100% Portland cement. It was also found that slaughterhouse-derived struvite could compete with commercial water-based fire retardant solution and exhibit acceptable flame resistance behavior for wooden structures. The versatility of sheep abattoir-oriented struvite was confirmed as an environmentally sustainable and clean by-product for different structural uses. [Display omitted] • First time use of SSW-derived struvite in ecologically friendly cement production. • Novel application of SSW-sourced struvite in fire resistant wood structure design. • More than 70% of NH 4 +-N removal/recovery from SSW via struvite precipitation. • Attractiveness and versatility of struvite in sustainable abattoir waste management. • Noticeable impact of partial cement substitution on reduction of CO 2 emissions. [ABSTRACT FROM AUTHOR]