Porous European mixes, PEMs, are a type of coated macadam in which the aggregate skeleton is designed to contain, when compacted, an air void content usually in excess of 20%. As a wearing course 50mm-thick on an impermeable base course, PEMs have well-known points of strength: reduction of splash and spray, mitigation of outdoor noise (high porosity, low flow resistivity), optimization of skid resistance at high speeds in wet condi-tions (high macrotexture). PEMs have several points of weakness: low bearing properties, clogging, variation of volumetrics over the time, variation of noise, texture, friction, and permeability performance over the time. Ten millions of square meters of PEMs are going to be definitely laid in Southern Italy (Calabria), but there is still considerable need for additional performance information for the use of Reclaimed Asphalt Pavement (RAP) in premium surface course mixes. Objectives and scopes were then focused into Recycling PEMs back to innovative, silent, permeable road surfaces. The following main key-issues were addressed: mitigating the drawback of clogging and its related consequences (decay of acoustic and drainagebility performance over the time); preserving traditional (bearing properties, skid resistance) and premium (silentness, drainagebility) performance; recycling high percentages of RAP-from-PEM. The following experimental plan was designed: 1. Materials selection; 2. Production; 3. Traditional tests on recycled PEMs; 4. Basic and advanced tests on surface and hydraulic properties of recycled PEMs; 5. Analyses and reports. High-RAP contents were tested. Design and construction features, including mix design and mixing procedures were addressed. Mechanical performance was adequate and environmental compatibility was achieved. Functional performance resulted very promis-ing and although several issues call for further research, the tests carried out are encouraging about the possibility of achieving a satisfactory level of surface performance. Practical applications and perspectives in rehabilitation, maintenance, and research are outlined.
Recycling PEMs back to innovative, silent, permeable road surfaces
PRATICÒ F G;GIUNTA M
2011-01-01
Abstract
Porous European mixes, PEMs, are a type of coated macadam in which the aggregate skeleton is designed to contain, when compacted, an air void content usually in excess of 20%. As a wearing course 50mm-thick on an impermeable base course, PEMs have well-known points of strength: reduction of splash and spray, mitigation of outdoor noise (high porosity, low flow resistivity), optimization of skid resistance at high speeds in wet condi-tions (high macrotexture). PEMs have several points of weakness: low bearing properties, clogging, variation of volumetrics over the time, variation of noise, texture, friction, and permeability performance over the time. Ten millions of square meters of PEMs are going to be definitely laid in Southern Italy (Calabria), but there is still considerable need for additional performance information for the use of Reclaimed Asphalt Pavement (RAP) in premium surface course mixes. Objectives and scopes were then focused into Recycling PEMs back to innovative, silent, permeable road surfaces. The following main key-issues were addressed: mitigating the drawback of clogging and its related consequences (decay of acoustic and drainagebility performance over the time); preserving traditional (bearing properties, skid resistance) and premium (silentness, drainagebility) performance; recycling high percentages of RAP-from-PEM. The following experimental plan was designed: 1. Materials selection; 2. Production; 3. Traditional tests on recycled PEMs; 4. Basic and advanced tests on surface and hydraulic properties of recycled PEMs; 5. Analyses and reports. High-RAP contents were tested. Design and construction features, including mix design and mixing procedures were addressed. Mechanical performance was adequate and environmental compatibility was achieved. Functional performance resulted very promis-ing and although several issues call for further research, the tests carried out are encouraging about the possibility of achieving a satisfactory level of surface performance. Practical applications and perspectives in rehabilitation, maintenance, and research are outlined.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
