Effectiveness of different admixtures on Atterberg limit and compaction characteristics of stabilized soil

Index properties of soared are the most crucial part of the soil, which impact construction activities due to the rapid growth of urbanization and industrialization. Soft soil is one of the most unstable soil which has a low strength and stiffness index due to its high liquid limit. Stabilization of soil by adding chemical or non-chemical based such as lime and cockle shell powder have proven to improve the index properties of soft soil. Lime and cockle shell powder is the most popular reinforcement materials used in the study on the soil reinforcement for soft soil. The use of lime and cockle shell powder as reinforcement materials in soil are proven effective. The study’s objective is to investigate the effectiveness of different admixtures used in the soil stabilization compared to lime and cockle shell powder on the effect of Atterberg limit and compaction characteristics of soft soil. It is shown the soil reinforcement in soil stabilization is functionally in improving mechanical properties of the soft soil. Meanwhile, the admixture in powder formed to act as a fine binder between soil and stabilizer agents. This will enhance the index properties of original soft soil such as Atterberg limit and compaction characteristics.

Cockle Shell as Mixing Ingredient in Concrete: A Review

The demand for the population is boosting the production of edible and non-edible products that produce by-products that result in emissions being thrown as waste. The successful cockle trade also creates vestiges of cockle shell that are thrown away as waste. Despite the effects of climate change, industrial activity including calcareous and granite mining to satisfy the need for cement and concrete production, respectively, cannot be prevented as more structures are developed worldwide. The mechanical properties of concrete containing crushed cockle shell as partial fine aggregate, coarse aggregate and cement replacement were examined and reported in this paper. Cockle shell powder was used as cement replacement up to 75%. To sum up, the use of cockle shell is an appealing option for the construction industry and sustainable green climate.

Vancomycin Loaded Alginate/Cockle Shell Powder Nanobiocomposite Bone Scaffold for Antibacterial and Drug Release Evaluation

Bacterial infection and biofilm formation is a major concern in orthopaedic implants and bone reconstructive surgery complications that may be addressed with localized drug delivery system. The potential use of a fabricated nanobiocomposite bone scaffold using alginate and nano cockle shell powder for drug release and antibacterial properties was investigated. Vancomycin loaded bone scaffolds were fabricated with 3 and 5 wt% vancomycin, respectively, while a non-drug loaded scaffold was used as controls. The mineralization of the scaffolds using simulated body fluid (SBF) as well as biofilm formation were evaluated using microscopic observations. Drug release study and antimicrobial activity of the eluent from each sampling period was tested for growth inhibition of Staphylococcus aureus and Staphylococcus epidermidis for a period of 21 days. Significant difference of cumulative amount of vancomycin eluted from scaffolds loaded with 5 wt% vancomycin compared to 3 wt% (p<0.05) were noted. Eluent from both groups showed inhibitory effect against bacterial strain tested for 21 days. The findings are further supported with histological observations of reduced biofilm formation by Staphylococcus epidermidis on surface of 5 wt% vancomycin loaded scaffolds compared to control scaffolds. Basic mineralization studies conducted showed no alteration in drug loaded scaffolds characteristics compared to control scaffolds. Findings from this study indicates antibacterial properties can be conferred to the fabricated bone scaffold with successful incorporation of vancomycin with potentials to be used for local drug delivery application.

Superiority of coarse eggshell as a calcium source over limestone, cockle shell, oyster shell, and fine eggshell in old laying hens

Chicken eggshell (ES) waste is a rich source of calcium carbonate (CaCO3); however, the potential of ES as dietary calcium (Ca) in old laying hens has not been explored. This study compared the effects of feeding limestone, cockle shell, oyster shell, fine ES, and coarse ES as the sole Ca source on production performance, egg quality, blood biochemical constituents, and tibia characteristics in old laying hens. A total of 450 ISA-Brown laying hens at 73 wk of age with similar egg production rate (EPR) were randomly assigned to 5 treatment groups (90 hens/group, 9 hens/replicate) for 7 wk. Dietary treatment groups comprised a corn-soybean meal based diet containing different Ca sources: (i) limestone (LS; < 2 mm and 2–4 mm mixed in the ratio of 3:7) as control, (ii) cockle shell (CS; 1–4 mm), (iii) oyster shell (OS; 3–16 mm), (iv) ES fine particles (ESF; < 1 mm), and (v) ES coarse particles (ESC; 3–5 mm). Results indicated that dietary inclusion of coarse ES particles significantly increased average egg weight (P < 0.001) and daily egg mass (P < 0.05), and decreased feed conversion ratio (P < 0.001) as compared with the other treatments. However, no significant differences in EPR, feed intake, cracked egg proportion, and mortality were observed among the dietary treatments (P > 0.05). Notably, the use of ESF led to a lower proportion of cracked eggs than ESC (P < 0.05). ESC fed hens produced the heaviest eggs whereas CS fed hens produced the lightest (P < 0.001); the particle size of ES also affected the egg weight (P < 0.05). The eggs from OS and ESC fed hens showed a greater albumen height in comparison to eggs from CS group (P < 0.05); but no significant difference was observed among the LS, OS, ESF, and ESC groups (P > 0.05). The yolk color was darker in the eggs of group ESF as compared with other dietary groups (P < 0.01). However, no significant effects on Haugh units and shell properties were observed among the treatments (P > 0.05). The blood biochemistry results were not affected by the dietary Ca (P > 0.05) except for lower levels of high-density lipoprotein percentage (HDL %) in OS and ESC fed hens (P < 0.05). The tibia characteristics including weight, length, width, and breaking strength did not differ among the dietary groups (P > 0.05). However, the ESC and OS fed hens showed higher tibia bone mineral density (BMD) than the other groups (P < 0.001). In conclusion, coarse ES as a sole Ca source had beneficial effects on the production performance, egg quality, and tibia BMD in old laying hens.

Performance of Porous Asphalt Mixture Containing Seashell as Aggregate Replacement

Porous asphalt pavement is mainly used for parking lots which able to let water to drain through the pavement surface into a stone recharge bed and infiltrate into soils under the pavement. This study is to investigate the performance of seashell in porous asphalt and determine the image analysis. The seashell used in this study is cockle shell. The strength of seashell was determined through the Aggregate Impact Value Test (AIV) and Aggregate Crushing Value Test (ACV). The grade of bitumen used was grade 60/70. The porous asphalt volumetric properties was determined through Marshall Stablity Test. The permeability coefficient of sample that contain seashell as aggregate replacement was determined through Permeability Test. Generally, the results shows that the seashell’s percentage loss (AIV and ACV) is suitable use for porous asphalt mixture, where the percentage of loss for AIV and ACV was 27.84% and 7.65% respectively. Based on the Marshall Test, porous asphalt that containing seashell as aggregate replacement shows a different result, where it had lower stability value and it can increase the bulk density of porous asphalt mixture. Furthermore, the permeability coefficient also increase. The surface of seashell able to bond with bitumen. Lastly, the trend of VFA and VTM value is effected by the surface and position of seashell in the porous asphalt sample.

Analysis of Cadmium (Cd) and Lead (Pb) Heavy Metal Content in Shell and Mangroves at Bima Bay

This study aims to determine the levels of heavy metals (Cd) and (Pb) in shellfishes and mangroves at Bima bay. The results showed that bivalves and mangrove tissue were analyzed for heavy metal content in the form of lead (Pb), and Cadmium (Cd) using an Atomic Absorption Spectrophotometer. From tissue analysis, it indicates that the content of heavy metals lead (Pb) in 3 species of Shellfish which showed different results; Blood shells (Anadaragranosa) of 0.756 ppm, Hiatula shells (Hiatula chinensis) 1.59 ppm, and Shells (Siliqua winteriana) 1.171 ppm. Cadmium (Cd) metals in Shells are each found; Cockle shell (Anadara granosa) of 0.802 ppm, Hiatula shells (Hiatula chinensis) 0.334 ppm and Shells (Siliqua winteriana) 0.066 ppm. The content of lead metal (Pb) in the tissue of small mangrove leaves (Ryzophora apiculata) is 3.21 ppm and the mangrove leaves (Sonnerati aalba) is 3.74 ppm. For Cd levels in small mangrove leaves (Ryzophora apiculata) is 0.41 ppm while in mangrove leaves (Sonneratia alba) is 0.24 ppm