by Omar Alelweet  and Sara Pavia

Received: 09 June 2021;  Published: 13 October 2021;  doi: 10.21926/rpm.2104041

Alkali activated (AA) materials have been investigated for decades as an alternative to Portland cement (PC) products. Most consist of a silicate waste activated with alkalis, which leads to lower green-house gas emissions and a substantial drop in the use of unrenewable material resources. This paper studies the durability of AA materials made with a ground granulated blast furnace slag (GGBS) from Dublin, activated with sodium hydroxide (NaOH), and sodium silicate (Na2SiO3), both combined and separately, and cure [...]

by Pal S. Mangat  , Shahriar Abubakri  , Konstantinos Grigoriadis  and Vincenzo Starinieri

Received: 24 June 2021;  Published: 09 October 2021;  doi: 10.21926/rpm.2104040

Microwave curing of repair patches provides an energy efficient technique for rapid concrete repair. It has serious economic potential due to time and energy saving especially for repairs in cold weather which can cause work stoppages. However, the high temperatures resulting from the combination of microwave exposure and accelerated hydration of cementitious repair materials need to be investigated to prevent potential durability problems in concrete patch repairs. This paper investigates the time and magnitude of [...]

by Bhuamik Patel  , Yeswanthi Kamineni  , Shashank Gorityala  and M Hima Bindu

Received: 19 August 2021;  Published: 28 September 2021;  doi: 10.21926/rpm.2103039

Dental caries are one of the major causes of oral degeneration diseases. In order to treat dental-related diseases, it is often challenging and expensive. Recent literature has reported many advances in designing delivery systems utilizing polymers and novel biomaterials. Polymers play an important role in designing many nanoformulations like liposomes, polymeric micelles, polymeric nanoparticles, carbon-based nanoparticles, nano-hydroxyapatite, iron oxide, zirconia, silica, and silver nanoparticles were used to tr [...]

by Khaled Hassan  , Ian Sims  , Murray Reid  , Alex Smith  and Mohammed Al-Kuwari

Received: 18 April 2021;  Published: 26 September 2021;  doi: 10.21926/rpm.2103038

Wadi gravel is a local aggregate in Qatar that could contribute to enhanced sustainability by replacing expensive imported gabbro. The material needs to be processed before use to reduce sulfate content to acceptable levels. The paper presents the performance assessment of three full-scale buildings, variously made with 50% and 100% Wadi gravel and conventional gabbro concretes. Site monitoring up to four years in service demonstrated the strength development with age and resistance to the aggressive exposure condi [...]

by Selvaraju Sivamani  , Rajoo Baskar  and Balasubramanian Lakshmi

Received: 29 April 2021;  Published: 14 September 2021;  doi: 10.21926/rpm.2103037

One of the crucial steps in the enzymatic hydrolysis of biomass is pretreatment. We investigated the applicability of a hybrid pretreatment method, This involved acid treatment followed by alkali before the production of fermentable sugars from cassava stem. The substrate was initially treated with acid (1% oxalic acid at 100 °C for 2 h), followed by treatment with a 10% NaOH–urea mixture (by mixing 5 g each of NaOH and urea in 100 mL of water) at 100 °C for 1 h. A cellulose recovery of 98.55% was obtained with the [...]

by O.A. Kornienko  , S.V. Yushkevych  , A.V. Sameljuk  and O.R. Andrievskaya

Received: 24 May 2021;  Published: 02 September 2021;  doi: 10.21926/rpm.2103036

The phase equilibria and structural transformations in the ternary ZrO2-CeO2-Eu2O3 system at 1500 °C were studied by X-ray diffraction and scanning electron microscopy in the overall concentration range. The system was found to constitute fields of solid solutions based on the tetragonal (T) modification of ZrO2, cubic (C) and monoclinic (B) modifications of Eu2O3, cubic with a fluorite-type structure (F) modifications of CeO2 (ZrO2), and ordered intermediate phase with a pyrochlore-type structure of Eu2Zr2O [...]

by Athanasia Soultana  , Michael Galetakis  , Anthoula Vasiliou  , Konstantinos Komnitsas  and Despina Vamvuka

Received: 11 February 2021;  Published: 17 August 2021;  doi: 10.21926/rpm.2103035

Waste concrete is the most predominant constituent material among construction and demolition waste. Current waste concrete recycling is limited to the use of recycled concrete aggregates as a road-base material and less as aggregates in new concrete mixes. Further, the production of recycled concrete aggregates results in the generation of a high amount of fines, consisting mainly of cement paste particles. Hence, this study aims to produce the cement mortars using the upgraded recycled concrete aggregates (sand g [...]

by Sydney Katras  , Dejian Ma  , Ayman al Dayeh  and David Tipton

Received: 31 March 2021;  Published: 12 August 2021;  doi: 10.21926/rpm.2103034

Bisphenol A (BPA) is a widely used synthetic compound that has been identified as an endocrine disruptor. It has been linked to adverse health effects such as developmental defects, infertility in both men and women, cardiovascular disease, and obesity. There has been increased interest in BPA’s effects on the developing fetus and data has revealed that doses below the presumed safe dose can produce harmful effects. Orthodontic clear aligner therapy is a popular treatment modality that involves the patient we [...]

by Layachi Guelmine  and Hadda Hadjab

Received: 27 March 2021;  Published: 09 August 2021;  doi: 10.21926/rpm.2103033

The present study investigated the effect of reused rubber particles (RRP) on the deicer salt durability of ordinary concrete. Four mixtures were designed, a control concrete (CC) and three other rubber concretes obtained by partial substitution of natural dune sand aggregate with reused rubber particles with 0%, 3%, 6%, and 9% w/w. All studied concretes were subjected to the combined effect of freeze/thaw (56 and 120) cycles with the deicer salt solution of 3% NaCl. The results indicated that RRP improved the deic [...]

by Mônica Batista Leite  and Paulo Roberto Lopes Lima

Received: 07 March 2021;  Published: 28 July 2021;  doi: 10.21926/rpm.2103032

The production of concrete using recycled aggregates, obtained from the processing of construction and demolition waste, is extensively practiced worldwide. However, the effect of simultaneous adding fine recycled aggregate and the recycled coarse aggregate on the mechanical properties of concrete is still unfamiliar. This work aims to evaluate the influence of the water/cement ratio (WC Ratio), the fine recycled aggregate content (%FRA), the coarse recycled aggregate content (%CRA), as well as the interaction betw [...]