Assessment of high strength and light weight aggregate concrete properties using ultrasonic pulse velocity technique
In this study, the ultrasonic pulse velocity technique as a non-destructive testing of concrete was used to assess the effect of some criteria on high strength and light weight aggregate concrete. The study included several concrete mix design with ages of 7, 28 and 90 days. The effect of age, cement content, water ratio and slump on two concrete types was studied and discussed. The use of ultrasonic pulse velocity technique to assessconcrete strength and quality was a good choice for effects determination. 
 
   
 
 Key words: Non destructive testing (NDT), ultrasonic pulse velocity (UPV), compressive strength, regression analysis.
Evaluation of concrete made with crushed limestone aggregate based on ultrasonic pulse velocity
Abstract Ultrasonic pulse velocity is one of the non-destructive tests to assess construction materials that have more advantages. It has been used to determine concrete quality by using regression analysis models between compressive strength and ultrasonic pulse velocity values. However, it is not reliable without a calibration curve. For this study, 100 concrete mixtures were prepared with crushed limestone aggregate obtained in the Yucatan Peninsula. The results from the compressive strength and the ultrasonic pulse velocity tests allowed the proposal of a criterion to qualify the concrete quality, without the use of calibration curves, based on the quality of the aggregate employed.
Growth from Solutions
Growth from solutions is the crystallization of a compound whose chemical composition differs markedly from that of the initial liquid phase. Commonly used solvents are water, multicomponent aqueous or nonaqueous solutions, and melts of some chemical compounds. Differentiations are made based on growth temperatures and on the chemical nature of the solvent. In growth from low-temperature aqueous solutions, the temperatures generally do not exceed 80–90°C; in growth from superheated aqueous solutions (hydrothermal method), they reach 800°C, and in growth from salt melts (molten-salt, flux, or fluxed melt growth), they usually do not exceed 1200–1300°C, but sometimes reach 1500°C.