Josipa Domitrović

Application of GPR and FWD in Assessing Pavement Bearing Capacity

Abstract The process of pavement maintenance and rehabilitation starts by collecting the data which will form the base for evaluation of pavement functional and structural condition. Collection of data can be performed by destructive and non-destructive testing. Usually preferred are the non-destructive methods, that do not damage the pavement, and the process of pavement evaluation is objective and repeatable. Non-destructive testing methods are becoming more and more popular, especially for assessing the structural condition of the pavement. Non-destructive testing by a Falling Weight Deflectometer (FWD) and the analysis of so collected data by the process of backcalculations is today the usual tool for assessing pavement bearing capacity. One of the basic input parameters for analysis of the data collected by FWD is pavement layers thickness. The practice in Croatia is to determine pavement layers thickness by coring. This destructive method affects pavement integrity, so the number of such tests should be kept to the minimum. By coring the accurate thickness of all pavement layers is obtained on specific point locations. Thus, numerous deviations in layer thickness remain unnoticed, and in the end, use of such data for the process of backcalculations does not provide ac urate values of layer moduli. Coring can be replaced with non-destructive method of testing by Ground Penetrating Radar (GPR), which provides continuous information on thickness of all pavement layers. The paper shows the method for assessing the bearing capacity of the pavement based on the data collected by FWD, GPR and coring. The calculation for layer moduli was performed by the ELMOD software, separately for the layers thickness data obtained by coring, and separately for the thickness obtained by GPR tests. Analysis and comparison of the results of calculated elasticity moduli obtained by using various methods for collecting layer thickness data were performed in the paper.

Application of an artificial neural network in pavement management system

The era of intensive construction of new roads is behind us, so road agencies are now focused on maintaining and preserving existing pavement surfaces. As they are faced with limited founds for maintenance it is important to utilize the money by selecting the best maintenance strategy. Selection of appropriate maintenance strategy is a complex task which includes factors such as current condition of the pavement, road classification, traffic volume and type of pavement distress. These factors can be automated and implemented in pavement management systems to achieve standardised approach to road pavement assessment and management. One of the key components of a pavement management systems are pavement performance prediction models which simulate pavement deterioration process and forecast its condition over time, one of such model is artificial neural network. This paper analyzes the possibility of using artificial neural networks in pavement management systems for evaluation of existing pavement condition and its possible application for defining the maintenance strategy of state roads. Backpropagation algorithm was applied on 481, 3 km of state road in Osijek-Baranja County which represents 7% of total length of national road network in Croatia. Obtained results indicated that artificial neural networks can be used for optimization of maintenance or rehabilitation strategies as well as assessment of pavement condition at project and network level.

Svojstva mješavina za izradu nevezanih nosivih slojeva s dodatkom recikliranog asfalta

U radu je istražena mogucnost primjene recikliranog asfalta kao zamjene za prirodni agregat u mjesavinama za izradu nevezanih nosivih slojeva. Istraživanje je provedeno na mjesavinama u kojima je određeni udio prirodnog agregata (vapnenca, sljunka) zamijenjen recikliranim asfaltom. Programom istraživanja obuhvacena su ispitivanja granulometrijskog sastava, parametara zbijanja, fizikalno-mehanickih svojstava i nosivosti mjesavina. Rezultati pokazuju da reciklirani asfalt, u određenom udjelu, može biti prikladna zamjena za prirodni agregat.U radu je istražena mogucnost primjene recikliranog asfalta kao zamjene za prirodni agregat u mjesavinama za izradu nevezanih nosivih slojeva. Ist

Prethodno priopćenje Svojstva mješavina za izradu nevezanih nosivih slojeva s dodatkom recikliranog asfalta

U radu je istražena mogucnost primjene recikliranog asfalta kao zamjene za prirodni agregat u mjesavinama za izradu nevezanih nosivih slojeva. Istraživanje je provedeno na mjesavinama u kojima je određeni udio prirodnog agregata (vapnenca, sljunka) zamijenjen recikliranim asfaltom. Programom istraživanja obuhvacena su ispitivanja granulometrijskog sastava, parametara zbijanja, fizikalno-mehanickih svojstava i nosivosti mjesavina. Rezultati pokazuju da reciklirani asfalt, u određenom udjelu, može biti prikladna zamjena za prirodni agregat.U radu je istražena mogucnost primjene recikliranog asfalta kao zamjene za prirodni agregat u mjesavinama za izradu nevezanih nosivih slojeva. Ist

Properties of unbound base course mixes with recycled asphalt

U radu je istražena mogucnost primjene recikliranog asfalta kao zamjene za prirodni agregat u mjesavinama za izradu nevezanih nosivih slojeva. Istraživanje je provedeno na mjesavinama u kojima je određeni udio prirodnog agregata (vapnenca, sljunka) zamijenjen recikliranim asfaltom. Programom istraživanja obuhvacena su ispitivanja granulometrijskog sastava, parametara zbijanja, fizikalno-mehanickih svojstava i nosivosti mjesavina. Rezultati pokazuju da reciklirani asfalt, u određenom udjelu, može biti prikladna zamjena za prirodni agregat.U radu je istražena mogucnost primjene recikliranog asfalta kao zamjene za prirodni agregat u mjesavinama za izradu nevezanih nosivih slojeva. Ist