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Article
Publication date: 24 April 2024

Shahriar Abubakri, Pritpal S. Mangat, Konstantinos Grigoriadis and Vincenzo Starinieri

Microwave curing (MC) can facilitate rapid concrete repair in cold climates without using conventional accelerated curing technologies which are environmentally unsustainable…

Abstract

Purpose

Microwave curing (MC) can facilitate rapid concrete repair in cold climates without using conventional accelerated curing technologies which are environmentally unsustainable. Accelerated curing of concrete under MC can contribute to the decarbonisation of the environment and provide economies in construction in several ways such as reducing construction time, energy efficiency, lower cement content, lower carbonation risk and reducing emissions from equipment.

Design/methodology/approach

The paper investigates moisture loss and pore properties of six cement-based proprietary concrete repair materials subjected to MC. The impact of MC on these properties is critically important for its successful implementation in practice and current literature lacks this information. Specimens were microwave cured for 40–45 min to surface temperatures between 39.9 and 44.1 °C. The fast-setting repair material was microwave cured for 15 min to 40.7 °C. MC causes a higher water loss which shows the importance of preventing drying during MC and the following 24 h.

Findings

Portland cement-based normal density repair mortars, including materials incorporating pfa and polymer latex, benefit from the thermal effect of MC on hydration, resulting in up to 24% reduction in porosity relative to normal curing. Low density and flowing repair materials suffer an increase in porosity up to 16% due to MC. The moisture loss at the end of MC and after 24h is related to the mix water content and porosity, respectively.

Originality/value

The research on the application of MC for rapid repair of concrete is original. The research was funded by the European commission following a very rigorous and competitive review process which ensured its originality. Original data on the parameters of porosity and moisture loss under MC are provided for different generic cementitious repair materials which have not been studied before. Application of MC to concrete construction especially in cold climates will provide environmental, economic and energy benefits.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 8 April 2020

Stephanos Papadamou, Costas Siriopoulos and Nikolaos A. Kyriazis

This paper presents an integrated overview of the empirical literature on the impact of all forms of unconventional monetary policy on macroeconomic variables and on markets.

1376

Abstract

Purpose

This paper presents an integrated overview of the empirical literature on the impact of all forms of unconventional monetary policy on macroeconomic variables and on markets.

Design/methodology/approach

This survey covers the findings concerning portfolio rebalancing, signaling, liquidity, bank lending and confidence channels.

Findings

The positive effect of QE announcements on stock and bond prices seems to be unified across studies. A contagion effect from US QE to other emerging markets is identified, while currency devaluation is present in most cases for the country that its central bank adopted such policies. Moreover, impacts of non-conventional practices on GDP, inflation and unemployment are examined. The studies presenting weak instead of strong positive effects on inflation are more, and these studies, also, present weak positive effects on GDP growth.

Originality/value

Based on the large body of research on non-conventional action taking, this is the first survey including effects of each country that adopted quantitative easing (QE) measures and that provides results from every methodology employed in order to estimate unconventional practices' impacts.

Details

Journal of Economic Studies, vol. 47 no. 7
Type: Research Article
ISSN: 0144-3585

Keywords

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