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Author: Abdulkareem, Qasim Hussein

Supervisor: Assistant Professor: Noureldin Mohamed

Advisor(s): Non 

Funding: Non 

Abstract: 

This thesis investigates the fire performance of reinforced concrete (RC) structures through a comprehensive analysis of published simulation studies, benchmark experiments, and recent advancements in material technologies. No original simulations were performed. Instead, the study synthesizes existing research on ordinary Portland cement (OPC) concrete, geopolymer concrete (GPC), and ultra-high-performance concrete (UHPC), focusing on thermal stability, spalling resistance, and post-fire residual strength.

Comparative findings are drawn from peer-reviewed finite element simulations using ABAQUS and SAFIR, as well as fire exposure modelling via Fire Dynamics Simulator (FDS), validated against full-scale benchmark tests (e.g., Cardington, NIST) and real-case fire incidents. The review con-firms that GPC and fiber-reinforced UHPC outperform conventional OPC under elevated temperatures.

This thesis identifies critical limitations in prescriptive fire codes such as ISO 834, ACI 216.1, and EN 1992-1-2, which often fail to address nonlinear degradation and material-specific behaviour. In response, the study advocates for simulation-informed, performance-based fire design (PBFD), grounded in published evidence. Targeted recommendations are proposed to support structural resilience, code modernization, and sustainable material integration in fire-exposed RC infrastructure. 

Author: Faisal Umer

Supervisor: Sanandam Bordoloi 

Advisor: DSc Fan Zhang

Abstract: 

The performance of asphalt pavements is highly dependent on the properties of binders and aggregates used in their construction. The availability of new multi-sourced binders in Finnish road construction market requires their mechanical performance evaluation to determine their suitability for local climatic conditions. Furthermore, the sustainability goals make it essential to incorporate emission measurements in optimizing the binder selection process. 

This study investigated the mechanical performance and emission characteristics of bituminous binders from multiple suppliers in establishing a comprehensive assessment framework for Finnish road materials. The research particularly focused on analysing the impact of binder source, penetration grade and aggregates in dictating mixture performance and emission behaviour. Asphalt mixtures made using two binder grades (50/70 and 70/100) from three different suppliers (A, B, C) and two aggregates (Lokonmäki and MalmgÃ¥rd) were tested. The mechanical characterization included tests for tensile strength, moisture sensitivity, dynamic creep, stiffness, abrasion and low-temperature cracking resistance over a wide range of temperature and moisture conditions. Emission measurements were conducted for 50/70, 70/100 and 160/220 grade binders using Gasera 1 analyser. 

Results demonstrated that binders exhibited source dependency in terms of their mechanical behaviour and emissions. It was observed that mixtures with B-sourced 50/70 grade binder showed superior strength, stiffness and durability in combination with Malmgård aggregates while 70/100 grade binders resulted in better cracking and abrasion resistance with Lokonmäki aggregates. Malmgård aggregates showed better strength while Lokonmäki aggregates provided good moisture resistance and durability against abrasion. In addition, emissions analysis revealed that all binders emitted varying quantities of water vapour, CO2, CO, acetone, SO2 and total volatile organic compounds based on their thermal stability and chemical compositions. The emission levels increased as a function of temperature and approached a steady state value over continuous heating of the binders with lowest emissions recorded for A-sourced binders.

Overall, the observations showed that the binder source and grade have influence on both the mechanical performance and emissions. The findings support the utilization of an assessment framework combining mechanical and emissions analyses for sustainable binder selection.

°Õ±ð°ì¾±Âáä: Simo Kauppila

Valvoja: Prof. Mikael Rinne

Ohjaaja: DI Meeri Kaartinen

Rahoitus: YIT Infra Oy, Ruskon Betoni Oy, Master Builders Solutions Finland Oy

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