Composite cement mortars based on marine sediments and oyster shell powder

Abstract

Additions of dredged marine sediments and oyster shell powder (OS) as cement substitute materials in mortars are examined by several techniques. The sediments have high water and chloride contents and calcite, quartz, illite and kaolinite as principal minerals. The OS powders are entirely composed of calcium carbonate and traces of other impurities. Four mixtures of treated sediments and OS powders at 650 °C and 850 °C are added to Portland cement at 8%, 16% and 33% by weight. The hydration of composite pastes is followed by calorimetric tests, the porosity accessible to water, the bulk density, the permeability to gas, the compressive strength and the accelerated carbonation resistance are measured. In general, the increase of addition amounts reduced the performance of mortars. However, a reduction of gas permeability was observed when the addition was up to 33%. Around 16% of addition, the compressive strength and carbonation resistance were improved. RESUMEN: Morteros de cemento basado en sedimentos marinos y polvo de concha de ostra.En este trabajo se ha valorado la sustitución de cemento en morteros por sedimentos marinos dragados y polvo de concha de ostra (OS). Los sedimentos tienen altos contenidos de agua, cloruros, calcita, cuarzo, illita y caolinita como minerales principales. Los polvos OS están compuestos de carbonato cálcico y trazas de otras impurezas. Se añadieron a un cemento Portland, cuatro mezclas de los sedimentos y polvos de OS tratados a 650 °C y 850 °C en proporciones del 8%, 16% y 33% en peso. La hidratación de pastas se estudió a través de calorimetría. Se estudió además la porosidad accesible al agua, densidad aparente, permeabilidad al gas, resistencia a compresión y carbonatación acelerada. En general, un aumento en la adición produjo una reducción del rendimiento de los morteros. Se observó, sin embargo, una reducción de la permeabilidad a los gases con porcentajes de adición de hasta el 33%. Con valores del 16% de sustitución, mejoraron las resistencias mecánicas y la resistencia frente a la carbonatación.

Sustainable use of seashells as binder in concrete production: Prospect and challenges

“…13.6, 13.9, and 29.9, respectively. Particles with needle-like form were also noticed in the Scanning Electron Microscope (SEM) micrographs for ground oyster shells [33]. Fig.…”

“…Portland cement [23,30,31] Cockle [23,29] Mussel [23,31] Oyster [23,28,[31][32][33] Periwinkle [32] Mollusk [31] Clam [23] Snail shell [32] Specific gravity 3. 13.6, 13.9, and 29.9, respectively.…”

Mechanical and durability assessment of concrete containing seashells: A review

“…With the application of a high temperature of about 500 to 1000 •C, CaCO 3 converts into carbon and calcium oxide (CaO) (Djobo et al, 2016;Li et al, 2015;Olivia & Oktaviani, 2017;Othman et al, 2013). The calcination process through heat can significantly increase pH value and influence the compound formed in the XRD dif-fractogram, most specifically CaO or calcite peaks (Chiou et al, 2014;Ez-Zaki et al, 2016;Yao et al, 2014). Abdulfattah (2001) chemical tests conducted in line with the Nigerian standard show that oyster shells, snail shells, and periwinkle shells contain a high percentage of SiO and CaO.…”

Produção e gestão sustentáveis: experiências e debates

“…Essa resolução visa facilitar a gestão da responsabilidade ambiental, corroborando a definição de estratégias de destinação de resíduos e a identificação de tecnologias de eliminação, além de contribuir para inserir os resíduos gerados em uma economia circular com foco no ecodesenvolvimento da cadeia produtiva da construção civil 76 . KUO et al, 3013;LI et al, 2015;EZ-ZAKI et al, 2016;.…”