3263
Applicability of Municipal Solid Waste (MSW) Incineration Ash in Road Pavements
Base
Utilisation de cendres d’incinération de déchets solides municipaux (MSW) dans la couche de base
de chaussée
Vizcarra G., Szeliga L., Casagrande M.
Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil
Motta L.
Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
ABSTRACT: This study presents the characteristics of Municipal Solid Waste (MSW) incineration ash, by-product obtained from
electric energy generation power plant in Rio de Janeiro - Brazil, to evaluate its applicability in base road pavements layers through
the ash mixture with a non-lateritic regional clay soil with very poor mechanical behavior. Chemical, physical, mechanical tests and
the mechanistic-empirical design for a typical pavement structure were carried out on the pure soil and also in the soil mixtures with
the addition of different ash content (20% and 40%). MSW fly ash reduced expansion of the material, showing increase in the resilient
modulus value with time of cure, load cycle number and reduction of mixture water content. Permanent deformation tests showed
mixture soil-MSW fly ash reached a state of plastic accommodation. A typical pavement design was carried out by comparing
between pure soil and mixture soil-MSW fly ash; the results showed that it is feasible utilize it in low traffic road pavements,
highlighting the positive work of MSW fly ash and its environmental advantages.
RÉSUMÉ: Cette étude présente les caractéristiques des cendres d'incinération des déchets solides municipaux (MSW), un sous-
produit obtenu à partir d'une centrale de production d'électricité à Rio de Janeiro - Brésil, afin d'évaluer son applicabilité en tant que
couche de base des chaussées en mélangeant la cendre avec un sol argileux non latéritique régional de comportement mécanique
inacceptable à cet effet. Des essais chimiques, physiques, mécaniques,ainsi que la conception mécaniste-empirique d'une structure de
chaussée typique ont été effectués sur le sol pur et aussi sur le mélange de sol avec addition de différentes concentrations de cendres
volantes de MSW (20% et 40%). L'inclusion des cendres a réduit l'expansion du sol, indiquant une augmentation de la valeur du
module résilient avec le temps de durcissement, le nombre de cycles de charge et la réduction de l'humidité du mélange. Des essais de
déformation permanente ont montré que le mélange de sol-cendres volantes des déchets solides municipaux a atteint un stade de
déformation plastique. La conception d'une chaussée typique a été réalisée pour comparer le sol pur et le mélange de sol-cendres
volantes des déchets solides municipaux, les résultats ont montré que son utilisation est possible dans des chaussées de faible
volume de trafic, mettant en évidence l'utilisation positive de ces cendres et ses avantages socio-économiques et environnementaux.
KEYWORDS: MSW fly ash, pavement, deformability properties, permanent deformation, resilient modulus.
1 INTRODUCTION.
This study evaluates the application of fly ash obtained from
incineration of Municipal Solid Waste (MSW) use in base
layers of pavements, by mixing the ashes with a non-lateritic
regional clay soil. The Usina Verde is a privately held company
located in the Federal University of Rio de Janeiro, and aims to
provide environmental solutions for the disposal of municipal
solid waste, through incineration with energy co-generation.
The Usina Verde receives, daily, 30 tons of MSW Company's
Waste Disposal of Rio de Janeiro. In sorting, recyclable
materials are segregated manually along with the use of metal
detectors; after this process, the composition of MSW is
principally organic matter (88%), plastic (10%) and rubber
(2%). The MSW is then crushed and separated as fine material
and sent to drying. These wastes are sent to the incinerator,
which operates at a temperature of 950ºC.
At the end of the incineration process are obtained fly ash
and bottom ash, being from 8 to 10% by volume of the two
ashes, which represent about 80% of bottom ash and 20% of fly
ash (Fontes 2008).
2 OBJECTIVES
The objective of the investigations is to study the effect of
MSW fly ash addition on the soil, evaluating deformability and
expansibility properties, also thickness layer pavements base of
soil with and without MSW fly ash
3 EXPERIMENTAL INVESTIGATION
3.1 Materials and properties
The non-lateritic clay soil in study came from a deposit located
in the city of Campo Grande, Rio de Janeiro state. Fly ash
comes from the burning of municipal solid waste (MSW) at
Usina Verde, which is located on Rio de Janeiro / RJ. The tests
performed at Pontifical Catholic University of Rio de Janeiro
and Federal University of Rio de Janeiro, aiming to characterize
and evaluate the soil and soil-MSW fly ash mixtures. Since
there was no research evidence previous to this topic, 20% and
40% as percentages of fly ash were utilized to add to the soil.
The symbols used in this study, which describe the materials
and mixtures with percent in weight, are presented in Table 1.
