Developing Guidelines for Assessing the Effectiveness of Intelligent Compaction Technology

Many factors affect pavement compaction quality, which can vary. Such variability may result in an additional number of passes required, extended working hours, higher energy consumption, and negative environmental impacts. The use of Intelligent Compaction (IC) technology during construction can improve the quality and longevity of pavement structures while reducing risk for contractors and project owners alike. This study develops guidelines for the implementation of IC in the compaction of pavement layers as well as performing a preliminary life-cycle cost analysis (LCCA) of IC technology compared to the conventional compaction approach. The environmental impacts of the improved construction process were quantified based on limited data available from the case studies. The LCCA performed in this study consisted of different scenarios in which the number of operating hours was evaluated to estimate the cost efficiency of the intelligent compaction technique during construction. The analyses showed a reduction in energy consumption and the production of greenhouse gas (GHG) emissions with the use of intelligent compaction. The LCCA showed that the use of IC technology may reduce the construction and maintenance costs in addition to enhancing the quality control and quality assurance (QC/QA) process. However, a more comprehensive analysis is required to fully quantify the benefits and establish more accurate performance indicators. A draft version of the preliminary guidelines for implementation of IC technology and long-term monitoring of the performance of pavement layers compacted thereby is also included in this report

A comprehensive experimental study on the performance of pumice powder in self-compacting concrete (SCC)

This study presents results on the performance of self-compacting concrete (SCC) mixtures containing pumice powder as a pozzolan in various proportions. The required superplasticizer dosage, used to obtain the desired initial slump flow, was determined when compared to mixtures containing fly ash or slag. The incorporation of cheap natural pozzolans as an alternative to cementitious materials can improve the fresh properties and durability of concrete. However, the reactivity of natural pozzolans, such as pumice, specifically in the early ages, is always a concern when using these supplementary materials. To identify the effects of pumice powder on workability retention of SCC mixtures, the slumps were measured with regards to time elapsed. The effects of pumice, fly ash, and slag on the self-consolidating properties such as slump flow, V-funnel flow, U-box, and J-ring flow, as well as compressive strength, electrical resistivity, and water absorption were investigated. The ordinary Portland cement was partially replaced between 10 and 50% by pumice, fly ash or slag, and the optimum cement replacement dosage for each supplementary cementitious materials (SCMs) is proposed based on a significance factor in different tests. The test results indicated that SCC mixtures containing pumice powder offer greater performance compared to other SCMs