Even though a lot of research has been carried out concerning the preparation of carbonate apatite (CHA), they were related to CHA in the form of powder. In the present study, macroporous CHA bone substitutes were prepared through composition-transformation of gypsum and Ca-hydroxide. Here, we investigated the effect of added Ca-hydroxide to gypsum, carbonation periods, and hydrothermal tempera...

To evaluate the effect of gypsum and manure on the yield and quality of sugarcane and properties of sodic soils, an experiment was conducted on farmer’s field at Dosehra area, District Charsadda during Kharif 2004. Ten treatments comprised of control (T1), gypsum @ 25 % of the soil requirement (T2), gypsum @ 50 % (T3), gypsum @ 75 % (T4), gypsum @ 100 % (T5), farm yard manure (FYM) @ 20 tons ha...

Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP)...

An Ultic Haploxeralf soil collected from ridges built into the slopes of the Coastal Mountain Range of Central Chile was used in applications of humic and fulvic acids (HFA) extracted from sludge from sewage treatment plants, in combination with gypsum (CaSO4). A total of 12 treatments were applied by combining four doses of HFA (0, 20, 30 and 40 t ha-1) with three doses of gypsum (0, 1.2 and 6...

Decay of trachyte used as building stone in urban environment was investigated through the analysis of crusts and patinas found on trachyte of the Euganean Hills in the Renaissance city walls of Padua, northeastern Italy. Mineralogical and microstructural characteristics of the alteration products, as well as majorand trace-element chemical composition, were determined by optical microscopy, SE...

Red Pompeian paintings, very famous for their deep intensity, are currently suffering from darkening. The origins of this darkening degradation are not clearly identified yet and remain a major issue for curators. In the specific case of cinnabar (HgS)-based red pigment, a photoinduced conversion into black metacinnabar is usually suspected. This work is focused on the blackening of red cinnaba...

This study discusses strength deterioration during the curing process of fly ash geopolymer and the use of CaSO4·2H2O (gypsum) as a deterioration remedy when the ash was synthesized using a 10M NaOH and Na-silicate solution. The strength decline was mainly due to the widespread formation of nanometer-sized cracks that were related to excessive Na and Si concentrations at an early age. Use of 2 ...

This study used two types of Recycled Concrete Aggregates (RCAs) with the same original virgin aggregate, but with different amounts of residual mortars. To verify that the mechanical properties of the concrete were affected by changing the unit volume of residual mortar, fresh mortar, and total mortar of the concrete, a series of paving concrete mixes were made using a modified equivalent mort...