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Volume 19, No. 34Journal 34

DOI:https://doi.org/10.15517/dyyvq106

Published November 13, 2025

Scientific Papers

  1. Alejandra Baldi-Sevilla, José Pablo Aguiar Moya, Mavis Montero, Luis Guillermo Loría Salazar (Author)

    Physicochemical approach of moisture damage susceptibility of binder-aggregate interfaces

    Moisture damage is one of the most severe distresses in pavements.  Among the causes of moisture damage is the poor quality of the binder-aggregate interface formed during mixing. The weakness of the interface might be due to a poor interaction between materials, which increases the susceptibility of binder of being removed from the aggregate surface by water. In this study, the quality of the binder-aggregate interface was approached by means of surface energy measurements of several binder-aggregate combinations. Two different aggregate sources were investigated: a limestone and a gravel, which were combined with three  asphalt binders: a diatoms-modified binder, a nanosilica-modified binder and neat binder as control. The proposed combinations were evaluated by means of physicochemical indicators related to moisture damage, such as work of adhesion, work of debonding and energy ratio. It was found that the quality of the interface is highly related to the aggregate source. Furthermore, several anti-strip additives were evaluated in terms of reduction of water susceptibility of the combinations and it was observed that their efficiency is dependent on the aggregate source with which the modified binder is combined. In summary, various parameters associated to interfaces can be obtained from surface energy measurements of binders and aggregates. This technique allows the physicochemical evaluation of binders and aggregates and the information obtained might be used as criteria for appropriate selection of water-resistant materials. 

  2. Federico Villalobos Carballo (Author)

    The concepts of funding and financing when developing projects through public private partnerships (PPP)

    The main objective of Public Private Partnerships (PPP) models is to generate efficiency gains throughout the project lifecycle. However, in a budget- constrained environment, PPPs are viewed as a tool for developing the projects which the government able to finance. That said, it is important to distinguish the concepts of project funding and project
    financing.
    Funding refers to the sources of income to repay for the project investments during its life: taxes and tariffs. Financing refers to money invested. Broadly speaking, financing could take the form of public debt, private debt or private equity. Therefore, private money is not "free money" and funding will be needed to repay for it. Having a clear understanding of these elements is crucial within the decision-making process in public infrastructure development.

  3. Marcos Alberto Martínez Martínez, Jonathan Agüero Valverde (Author)

    Spatial configuration of Cartago city and its relashionship with traffic volumes

    Spatial syntax studies the configuration of spatial elements and the relationships between them. For a city, these elements are the streets that form its road network. Spatial syntax seeks to stablish relationships between this spatial composition and urban characteristics such as the movement of people and vehicles, the land value, and the location commercial activities. This study seeks to determine the correlation between this configuration and the vehicular volume of the road network in the city of Cartago, Costa Rica. To obtain this correlation, a unit segment analysis was performed, establishing the priority of the roads at each intersection and gathering field information of the network. Subsequently, several statistical models were considered to find the best fit of the data. The highest correlation is achieved using an exponential multivariate model. Including a categorical variable for North-South streets with unidirectional flow considerably improves the fit of the model. On the other hand, considering only one variable leads to an overestimation of traffic volume for these cases. It is concluded that spatial syntax analysis is a fast and economical method that can provide a guide to execute more detailed studies on the current network and early stages of future projects.