Utilization of Crushed Pavement Blocks in Concrete: Assessment of Functional Properties and Environmental Impacts.

Václav Kočí,Jan Kočí,Jan Fořt,Lukáš Fiala,Izabela Hager,Jiří Šál,Robert Černý

doi:10.3390/ma14237361

Abstract

Production of concrete is connected to extensive energy demands, greenhouse gases production or primary sources depletion. Reflecting current economical, social, or environmental trends, there is strong pressure on mitigation these requirements and impacts. The exploitation of secondary- or waste materials in production processes has therefore a great potential which is not related solely to binders but also to fillers. In this light, this paper aims at thorough investigations of concrete mixtures with crushed concrete pavements as partial or full replacement of natural coarse aggregates. The research combines experimental techniques to quantify the influence of the substitution on basic physical, mechanical, and heat/moisture transport/storage parameters. The experimental data obtained are further exploited as input data for computational prediction of coupled heat and moisture transport to assess the influence of the aggregates substitution on hygrothermal performance of the built-in concretes. In the last step, the environmental impacts are assessed. Since the changes in the hygrothermal performance were found to be insignificant (i), the compressive strength were improved by up to 25% (ii) and most of the environmental impact indicators were decreased (iii) at the same time, the findings of the research presented predeterminate such a reuse strategy to wider application and use.

Highlights

Being started by the Portland cement production patented in 1824 [1], concrete has become one of the most popular materials
Of the tioned efforts, thisefforts, research at a thorough of the mixtures designed to aforementioned thisaims research aims at ainvestigation thorough investigation of the mixtures designed assess their material properties and hygrothermal performance as well their as to assess theirtomaterial properties and hygrothermal performance as well as to quantify quantify their mitigation of negative environmental impacts
The thorough experimental analyses of basic physical, heat and moisture transport, and storage parameters revealed that the substitution of the natural coarse aggregates for crushed concrete pavements at the end of their service life did not influence the material properties in a negative way

Summary

Introduction

Being started by the Portland cement production patented in 1824 [1], concrete has become one of the most popular materials. Being the most topical in the last years, the environmental protection efforts have probably the biggest impact these days. In this context, concrete has been branded as an ecohostile material whose production goes along with extensive carbon dioxide emissions [4,5], energy consumption [6], and primary sources depletion [7,8]. Utilization of byproducts or even waste materials turned out to be perspective in case of fillers as it saves primary resources and reduces landfilling necessities, generally improving the overall life cycle indicators. There are much more possibilities of what can be used [10]

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Conclusion