Several experimental studies have been done long time ago to calculate the fracture energy of concrete [2, 6]. Most of these studies neglected the loss of energy due to the frictional process in the mechanism of experimental set up. All these studies have used the indirect tensile testing method, as a suitable approach for determining the fracture energy of concrete of mature age [3, 7]. However all these experimental studies have not investigated the crack or the localization process of young age concrete yet. So, a view to evaluate the fracture energy of concrete and to study the fracture and localization process, it is described herein this study an experimental investigation. Fracture energy for the early ages of concrete is estimated experimentally considering the weather of Kingdome of Saudi Arabia. Several experiment specimens of different ages, sizes, lengths and end head specimens are prepared and assessed. The specimens in early age are tested out to calculate the fracture energy of concrete using a direct tension test, taking into consideration the loss of energy due to the frictional process in the mechanism of experimental set up. Also the crack localization is considered during the experiment, as dealing with the localized fracture. In this experiment work, the measurements reach to the post peak softening branch of concrete using the direct tension. Moreover, the fracture process of early age concrete is identified through an analytical study, using the Modified Lattice Model suggested earlier by the author [1, 19]. In the analytical study plastic modeling was done based on the Modified Lattice Model approach. A softening function to describe the fracture process of early age concrete which is proposed is used [11]. It is shown that the softening rule can be applied to simulate the fracture process of early age concrete using the Modified lattice Model. The results show that there is a fairly good agreement between the experimental data and the numerical results using the Modified Lattice Model. However, the change of different concrete ages results is quite the agreement with the numerical results but only using one case of gage length.

The Mn-Ferrite nanoparticles were prepared using citrate nitrate auto combustion method.The Multiwalled carbon nanotubes (MWCNTs) and MnFe2O4 nanoparticles were characterized by BET to measure the surface area. XRD data of MnFe2O4 nanoparticles clarified that the sample was formed in single phase spinel structure without any extra peaks indicating any secondary phase. The High-resolution transmission electron microscopy (HRTEM)micrograph of MnFe2O4 nanoparticles indicated that the particles are in an agglomerated state due to the absence of surfactant and high magnetic properties of Mn-Ferrite nanoparticles. Also, HRTEM micrograph showed that the walls of MWCNTs are straight having high crystallinity without any kinks. The mechanical properties were measured at different ratios of MWCNTs and nano-ferrite to cement. The obtained values indicated that the addition of MWCNTs and nano-ferrite increase the compressive

The Mn-Ferrite nanoparticles were prepared using citrate nitrate auto combustion method.The Multiwalled carbon nanotubes (MWCNTs) and MnFe2O4 nanoparticles were characterized by BET to measure the surface area. XRD data of MnFe2O4 nanoparticles clarified that the sample was formed in single phase spinel structure without any extra peaks indicating any secondary phase. The High-resolution transmission electron microscopy (HRTEM)micrograph of MnFe2O4 nanoparticles indicated that the particles are in an agglomerated state due to the absence of surfactant and high magnetic properties of Mn-Ferrite nanoparticles. Also, HRTEM micrograph showed that the walls of MWCNTs are straight having high crystallinity without any kinks. The mechanical properties were measured at different ratios of MWCNTs and nano-ferrite to cement. The obtained values indicated that the addition of MWCNTs and nano-ferrite increase the compressive

Mn-Ferrite nanoparticles were prepared using citrate auto combustion method. The prepared sample was characterized by X-ray diffraction (XRD), HRTEM and BET to measure the particle diameter and the surface area of the prepared sample. The data of XRD clarified that the sample was formed in single phase spinel structure without any extra peaks indicating non-existence of any secondary phase. The HRTEM micrograph indicated that the particles were in an agglomerated state due to the absence of surfactant and high magnetic properties of Mn-Ferrite nanoparticles. The mechanical properties were measured at different ratios of nano-Ferrite to concrete. The obtained values of mercury intrusion porosimetry (MIP) indicated that the addition of Mn-Ferrite nanoparticles increased the compressive strength and decreased the total intrusion volume. This was due to the rapid consuming of Ca(OH)2 which was formed during hydration of Portland cement especially at early ages due to the high reactivity of MnFe2O4 nanoparticles. Moreover, MnFe2O4 nanoparticles recovered the particle packing density of the blended cement, leading to a reduced volume of pores in the cement paste.

Mn-Ferrite nanoparticles were prepared using citrate auto combustion method. The prepared sample was characterized by X-ray diffraction (XRD), HRTEM and BET to measure the particle diameter and the surface area of the prepared sample. The data of XRD clarified that the sample was formed in single phase spinel structure without any extra peaks indicating non-existence of any secondary phase. The HRTEM micrograph indicated that the particles were in an agglomerated state due to the absence of surfactant and high magnetic properties of Mn-Ferrite nanoparticles. The mechanical properties were measured at different ratios of nano-Ferrite to concrete. The obtained values of mercury intrusion porosimetry (MIP) indicated that the addition of Mn-Ferrite nanoparticles increased the compressive strength and decreased the total intrusion volume. This was due to the rapid consuming of Ca(OH)2 which was formed during hydration of Portland cement especially at early ages due to the high reactivity of MnFe2O4 nanoparticles. Moreover, MnFe2O4 nanoparticles recovered the particle packing density of the blended cement, leading to a reduced volume of pores in the cement paste.

This article investigates trihalomethanes (THMs) production and simulates water age in Assiut drinking water system using WaterCAD software. Prechlorinated water samples were collected from Nazlet Abdellah water treatment plant and post-disinfected with chlorine/chloramines with different chlorine-to-nitrogen ratios (Cl2/N). Experiments have examined varying residence times, ratios of Cl2/N, pH conditions, and storage containers’ type on THMs formation. The results showed that as the residence time increased, THMs concentrations increased. Water age in Assiut drinking water distribution network reaches more than 10 h. Using chloramines instead of free chlorine for post-disinfection resulted in lowering THMs concentrations to 58.9 % after 48 h of disinfection. Ratios of Cl2/N (2:1–6:1) were comparable and effective on lowering THMs concentrations, and the most effective ratio was 4:1. Also, as the pH increased, the THMs increased. The measured THMs concentrations in chloraminated water stored in glass and plastic bottles were approximately the same.