Multivariate Optimization of Recycled Road Base Cold Mixtures with Foamed Bitumen

Abstract

The paper presents an approach for identifying the optimum range of foamed bitumen and Portland cement contents in recycled mineral-bitumen road base mixtures using simultaneous optimization of response variables (i.e. properties of mixtures estimated from statistical models) with the use of desirability functions. The 16 evaluated mixtures had a common aggregate composition comprising materials from existing pavement layers (reclaimed asphalt pavement and aggregates from recycled crushed stone base layer) and virgin material. The mixtures varied in foamed bitumen contents (2.0% -3.5%) and Portland cement contents (1.0% -2.5%). The investigated mixture parameters included: air void content (V m ), indirect tensile strength (ITS), tensile strength retained (TSR) and indirect tensile stiffness modulus (ITSM) at 25°C. The use of the desirability functions and desirability index allowed to identify the effective and optimum range of binding agent dosing for the recycled mixture with respect to all of the measured mixture properties.

Optimisation of bitumen emulsion properties for ballast stabilisation

“…A method that allows these different properties to be optimised across the different configurations analysed in this study had to be established. For this purpose an optimisation method was used that introduces desirability functions (DFs) that transform the parameters into desirability in the range [0,1], where 0 values are unacceptable whereas 1 means the most desirable properties (35). Two types of DF were proposed by Derringer & Suich (36): the first type defines a range of acceptability, using lower and upper limits and a target value; the second type is defined using only the lower and upper limits.…”

Estimated Valuation of the Cost of Road Construction with the Use of Composite Cationic Bituminous Structures

“…Using suggested technology of producing road covering attracts economy in value 11200-18500 $ per 1 km of repaired roads, consequently [2,8,12].…”

Wpływ Rodzaju Asfaltu Na Właściwości Lepkosprężyste Mieszanek Mineralno–cementowych Z Asfaltem Spienionym

“…Mieszanki wytwarzano w całości w laboratorium, symulując zastosowanie technologii recyklingu głębokiego na zimno, analogicznie jak w [4,8]. Oznaczenia wykonywano na rdzeniach o średnicy 100 mm i wysokości 150 mm wywierconych z próbek cylindrycznych o wymiarach 150 mm x 200 mm zagęszczanych w prasie żyratorowej.…”

“…W składzie badanych mieszanek MCAS o właściwościach podanych w [4,8] stosowano 50% destruktu asfaltowego, 30% destruktu kamiennego oraz 20% kruszywa doziarniającego. Jako środki wiążące stosowano cement klasy 32,5 w ilości 2% oraz asfalt spieniony w ilości 2,5%.…”