Abstract-This paper studies the strength development of lowstrength material (CLSM) is controlled by using waste paper sludge ash (WPSA) in CLSM mixtures without adding Portland cement. Series of four (4) compounds which is the CLSM containing 5%, 10%, 20% and 30% of waste paper sludge ash (WPSA) as a substitute for Portland cement. CLSM cubes the sizes of 100mm x 100mm x 100mm compressive strength were tested at age 7, 14 and 28days. It was found that this activity contributes to strength development pozzolonic paper waste sludge ash (WPSA) depending on the percentage of the added waste paper sludge ash. So, it was found that the activity pozzolonic has been activated by the alkaline and calcium hydroxide (Ca(OH) 2 ) contributed from recycled concrete aggregate (RCA). In this study, the alkaline releases when soaked in water for 28days. Compressive strength of controlled lowstrength materials affected by both the ratio of fine aggregate and coarse aggregate and mixture characteristics during maturation developed CLSM. Cube test results show that CLSM with a ratio of 1:2 and 1:1 RCA and 20mm recycled coarse aggregate, 30% of WPSA content expressed as mass percentage of RCA is to produce a uniform mixture with a constant highstrength (maximum strength of 6.04MPa).

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This paper presents the feasibility study of adding recycled Polyethylene Terephthalate (PET) fiber obtained from drinking water bottle as admixture material in the concrete. A few numbers of tests were conducted to determine the physical and mechanical properties of recycled PET fiber reinforced concrete such as slump test, compressive strength test and flexural strength test. The effect of incorporating the recycled PET fiber on various volume fractions of concrete by 0.5%, 1%, and 1.5% of weight of cement were experimentally investigated. The test specimens comprising of cubes and beams were prepared and tested at 3, 7, 14 and 28 days after curing process completed. Generally, it was found that the workability of concrete reinforced recycled PET has reduced as the volume fraction of PET fiber increased. The compressive strength of concrete reinforced recycled PET has reached the highest value at volume fraction of 0.5%. However, the flexural strength of concrete was significantly increased by incorporating 1.0% of recycled PET fiber. It can be concluded that the concrete which contains 0.5% of recycled PET fiber has the highest of average percentage of relative. Hence, it can be categorized as the optimum percentage of recycled PET fiber to be utilized in concrete. It is recommended to use recycled PET fiber in concrete for the construction of structures and infrastructures as a green construction material in order to achieve clean and sustainable environment in the year future.

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Self-Consolidating Concrete (SCC) is developing class of concrete materials that offers great potential to improved ease of positioning and cost through reduced time and labor. Generally, amount of Construction and Demolition Wastes (C&DW) are increased daily. Therefore, it is beneficial to final usage of coarse recycled concrete aggregate that produced from crushed concrete waste as a new construction solution. Researchers have found that waste materials have unique properties that could help in improving the quality of self-consolidating concrete produced. Therefore, reuse of RCA generated as the supplemental material for the replacement of aggregate are significant in reducing the environmental impact. This research was focused on the strength characteristic and the chloride permeability level of SCC containing RCA. The influence of RCA content in the range from 0% to 100% of Natural Aggregate (NA) to the strength characteristic and the chloride permeability level of SCC was identified and compared with SCC containing normal mixes. In this research, three (3) series of concrete specimens were cast with different water cement ratios (0.53, 0.49 and 0.45). The concrete specimens were subjected to strength at the age of 3, 7, 14, 21, 28, 56 and 90 days and durability at the age of 28, 56 and 90 days. The result shown that the compressive strength and chloride permeability of SCC containing 100% RCA replacement give better performance than the 0% RCA replacement. Based on the finding, SCC containing 100% RCA replacement can be categorized similar to conventional concrete hence it can be utilized for construction purposes. RCA can also acts as an alternative replacement in concrete for replacing the NA. Keywords: Strength Properties; Rapid Chloride Permeability Test; Self Consolidating Concrete; Recycled Concrete Aggregate