Novel approach to enhance the efficiency of mortar against radiations by co-incorporation of lead and boron compounds with calcium chloride.

Fabrication of heavy density mortar using aggregates reinforced with available solid inorganic chemical additives is of a great importance as a protective layer to mitigate radiations in nuclear facilities. The effect of lead oxide and borax decahydrate on the hydration kinetics was evaluated by determining setting time, leachability and compressive strength. To speed up the reaction, 0.

Evaluating the role of feldspar on the resistivity of alkali-activated slag towards seawater attack.

In this study, the effect of K-feldspar on the behavior of alkali-activated slag pastes (AAS) before and after exposure to seawater was evaluated by measuring the compressive strength and the microstructure. To achieve this objective, the mixtures were prepared upon partial replacement of ground granulated-blast furnace slag (GGBFS) with calcined and un-calcined feldspar fine particles (termed as FS and CFS) at levels ranging from 5 to 20%, by mass. Under processing conditions, the solidified specimens were immersed for 1, 7, 14, and 28 days in 100% RH at 40 ± 2 °C.

An investigation on the performance of lightweight mortar-based geopolymer containing high-volume LECA aggregate against high temperatures.

The influence of lightweight expanded clay aggregate (LECA) on the physico-mechanical properties and microstructure of geopolymer mortar containing slag binder alkali-activated with sodium silicate solution before and after exposure to thermal loads was investigated. In the current procedure, siliceous sand was partially substituted with LECA fine aggregate at levels of 0%, 25%, 50%, 75%, and 100%, by volume. The effect of LECA on the performance before exposure was evaluated by measuring flowability, water absorption, bulk density, thermal conductivity, and compressive strength.

Transapical aortic stenting: an initial case series.

Aims: The standard approach for thoracic endovascular aortic repair (TEVAR) is transfemoral; however, calcifications and tortuosity of the access vessels might be so extensive as to increase the operative risk markedly or preclude the procedure. This study evaluates the transapical approach as an alternative route for TEVAR in such patients.

Methods And Results: From June 2011 to July 2013, the institution's interdisciplinary board for aortic diseases initially denied TEVAR for eight patients with thoracic aortic pathology due to extensive calcification and tortuosity of the distal vessels.