Effects on cement after partial replacement with burned joss paper ash.

Area of Science:

• Construction Materials Science
• Environmental Engineering
• Sustainable Building

Background:

• Growing global environmental awareness necessitates sustainable solutions in construction.
• Traditional Chinese ancestor worship involves burning significant amounts of joss paper, generating substantial burned joss paper ash (BJPA).
• Landfilling BJPA presents environmental challenges, prompting research into alternative waste management strategies.

Purpose of the Study:

• To investigate the feasibility of recycling BJPA as a partial cement replacement in mortar.
• To evaluate the impact of incorporating calcined BJPA (CBJPA) on the physical and microstructural properties of mortar.

Main Methods:

• BJPA was calcined and used to replace cement in mortar at replacement levels of 0% to 30%.
• Macro-analyses included tests for setting time and compressive strength.
• Microstructural and chemical analyses utilized scanning electron microscopy-energy dispersive spectroscopy, X-ray diffraction, and thermal gravimetric analysis/differential thermal analysis.

Main Results:

• All mortar specimens with CBJPA replacement exhibited lower compressive strengths compared to the control group.
• Increasing CBJPA content led to reduced compressive strength and shorter setting times.
• Loose mortar structures and insufficient cementation of hydration products were observed, hindering expected pozzolanic reactions.

Conclusions:

• Replacing cement with CBJPA in mortar is not effective in improving strength.
• The pozzolanic potential of CBJPA in this application was not realized, leading to compromised mortar performance.
• Further research is needed to explore alternative recycling methods or applications for BJPA in construction materials.