Date of Publication

5-2025

Document Type

Master's Thesis

Degree Name

Bachelor of Science in Civil Engineering (Honors) - Ladderized

Subject Categories

Civil Engineering

College

Gokongwei College of Engineering

Department/Unit

Civil Engineering

Thesis Advisor

Cheryl Lyne C. Roxas

Defense Panel Chair

Daniel Nichol R. Valerio

Defense Panel Member

Jason Maximino C. Ongpeng

Maria Emilia P. Sevilla

Abstract (English)

The construction industry contributes roughly 40% of global carbon emissions, mainly from cement production, prompting research into more sustainable practices such as using supplementary cementitious materials (SCMs)—mostly industrial products with pozzolanic or cementitious properties—to partially replace cement in concrete. Due to its abundance, seawater is being explored as an alternative to freshwater, especially as concrete production consumes 9% of global industrial water. This study explores seawater as an alternative to freshwater and SCMs such as rice husk ash, silica fume, and fly ash as partial cement replacements in concrete production. Using three resort construction projects in the Philippines as case studies, the study evaluates the environmental, economic, and social sustainability of these alternatives through life cycle assessment, cost analysis, and professional survey. Results showed that 20% fly ash replacement with seawater consistently achieved the highest environmental performance by reducing carbon emissions by 164 million kg CO2-eq and freshwater consumption by 98.72%. The cost analysis revealed that freshwater OPC mixes are the most economical, while seawater and silica fume mixes are the most expensive due to transportation and material costs, with sensitivity analysis highlighting their vulnerability to inflation. While initial reluctance toward seawater use existed due to potential reinforcement corrosion, survey results indicated increased public acceptance. Using the fuzzy analytic hierarchy process, the optimal design mix was seawater with 20% fly ash replacement, ranking highest across all sustainability dimensions. The study concludes that seawater and SCM integration can significantly enhance concrete sustainability. However, further experimental studies are recommended to assess the long-term durability and corrosion resistance of seawater-mixed concrete with SCMs. Seawater also presents the potential for further exploration in other viable construction applications, including soil stabilization and compaction, as well as precast concrete elements in marine structures. Policy development and standardization are also crucial to promote the broader adoption of seawater and SCM-based concrete for sustainable and resource-efficient construction practices.

Abstract Format

html

Abstract (Filipino)

None

Abstract Format

html

Language

English

Format

Electronic

Keywords

Sustainable construction

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Embargo Period

5-2028

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Available for download on Monday, May 01, 2028

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