Boo Hyun Nam

Over the past decades, extensive studies on municipal solid waste incineration (MSWI) ashes have been performed to develop more effective recycling and waste management programs. Despite the large amount of research activities and the resulting improvements to MSWI ashes, the recycling programs for MSWI ashes are limited. For instance, although the U.S. generates more MSWI ashes than any other country in the world, its reuse/recycle programs are limited; bottom ash and fly ash are combined and d

With the continuous research efforts, sophisticated predictive molecular dynamics (MD) models for C-S-H have been developed, and the application of MD simulation has been expanded from fundamental understanding of C-S-H to nano-engineered cement composites. This paper comprehensively reviewed the current state of MD simulation on calcium-silicate-hydrate (C-S-H) and its diverse applications to nano-engineered cement composites, including carbon-based nanomaterials (i.e., carbon nanotube, graphen

Aggregate type and mineralogy are critical factors that influence the engineering properties of concrete. Temperature variations result in internal volume changes could potentially cause a network of micro-cracks leading to a reduction in the concrete’s compressive strength. The study specifically studied the effect of the type and mineralogy of fine and coarse aggregates in the normal strength concrete properties. As performance measures, the coefficient of thermal expansion (CTE) and compressi

Depressions due to sinkhole formation cause significant structural damages to buildings and civil infrastructure. Traditionally, visual inspection has been used to detect sinkholes, which is a subjective way and time- and labor-consuming. Remote sensing techniques have been introduced for morphometric studies of karst landscapes. This study presents a methodology for the probabilistic detection of sinkholes using LiDAR-derived digital elevation model (DEM) data. The proposed study provides benef

The magnitude of the overall settlement depends on several variables such as the compression index, Cc, and recompression index, Cr, which are determined by a consolidation test; however, the test is time consuming and labor intensive. Correlations have been developed to approximate these compressibility indexes. In this study, a data driven approach has been employed to estimate Cc and Cr. Support vector machines classification is used to determine the number of distinct models to be developed.

The object of this study is to investigate the feasibility of ball-milled graphene oxide nanoflakes (GONFs) produced by a mechanochemical process as an additive in Ordinary Portland Cement (OPC)-based paste and concrete. Different percentages of GONFs (0.01–1 wt. %) were added in OPC paste mix to find the optimum content of GONF in GONF-combined cement composites. To investigate the effect of the changes in the mix design on OPC paste, two mix design methods were employed: (1) Dry-mix, where GON

The main focus of this study is the characterisation of the municipal solid waste incineration (MSWI) ashes and their influence on engineering properties of cement paste when part of Portland cement is replaced with ground MSWI ashes. Petrographic examinations were performed in order to identify chemical composition of ashes and to determine their contents. To evaluate the main side effect of ashes when used in cement, the creation of network of bubbles due to the presence of aluminium, ashes, a

Current management practice, existing regulations, and environmental consequences of municipal solid waste incineration (MSWI) ash utilization were comprehensively reviewed. Efforts were made to physically and mechanically characterize MSWI bottom and fly ashes and also to evaluate their influence on the structural properties of Portland cement concrete (PCC) and hot-mix asphalt (HMA) when part of fine aggregate is replaced with the MSWI bottom ash. Fundamental properties of MSWI bottom ash and

This paper aims to investigate the effects of edge-oxidized graphene oxide nanoflakes (EOGO) on the mechanical properties and sorptivity of cement composites. The EOGO used in this study was produced by a mechanochemical process that assists the production of EOGO in large quantities at significantly reduced costs, enabling its practical use for infrastructure construction. The scope of this work includes the use of EOGO as an additive in cement composites, including cement paste and mortar. Thi

Structural evaluation provides valuable information about the expected behaviour and response of pavements and can be used at the network level of pavement management to prioritise projects. The falling weight deflectometer (FWD) can be used to identify the beginning and end of management sections and group pavement sections with similar structural capacities. The structural condition index (SCI) was developed as a screening tool for the pavement network-level evaluation, and the FWD data are us

This paper presents the implementation of the frequency ratio (FR) method to evaluate the contribution of every factor on sinkholes and develop a sinkhole susceptibility map for East Central Florida (ECF). The FR is a probabilistic method used to determine the correlation between sinkhole locations in the past and each sinkhole-related factor. ECF, vulnerable to sinkhole formation, was selected, and a sinkhole database (total 1,018 sinkholes) was adopted from the Florida Subsidence Incident Repo