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Published in Les Goring, Residential Surveying Matters and Building Terminology, 2023
Sharp sand: This is an important ingredient of concrete and of sand-and-cement mortar mixes for chimney-top flaunching and floor screeds, etc., where greater strength and longevity are required. It can be visually differentiated from soft sand by its slightly larger, coarser, angular-shaped structure – and, of course, it feels sharper than soft, round-shaped sand.
External rendering
Published in Derek Worthing, Nigel Dann, Roger Heath, of Houses, 2021
Derek Worthing, Nigel Dann, Roger Heath
A ‘sharp’ sand should be used for renders (i.e. a sand with angular particles); this is different from that used for masonry mortars, where a ‘soft’ sand, with more rounded particles, is usually specified. The sand should be clean and well graded (i.e. with a range of fine and coarse particle sizes). The grading is important as it affects the water/cement ratio: a badly graded sand requires a lot of water to achieve a workable mix. Shrinkage will occur as the excess water evaporates, causing stresses within the render which can result in cracking.
Upcycling agricultural and plastic waste for sustainable construction: a review
Published in Environmental Technology Reviews, 2023
Bilal Messahel, Nwakaego Onyenokporo, Emefa Takyie, Arash Beizaee, Muyiwa Oyinlola
Several researchers have investigated the possibility of converting these various forms of plastic waste into sustainable construction materials. Awoyera and Adesina [58] explored the various approaches to recycling plastic wastes and highlighted the opportunities and limitations of using plastic waste for construction. Kou et al. [59] investigated the use of recycled PVC granules waste to replace river sharp sand for concrete, highlighting that river sand is becoming a scarce natural resource in countries like China. Similarly, other researchers have investigated the use of shredded PET bottles in manufacturing compressed earth brick [60], incorporating plastic bottles in floor panels [61] and wall panels [62], plastic fibre-strengthened interlocking bricks suitable for load bearing application [63], incorporating polyurethane (PUR) foam waste particles in concrete [64] and using polyethylene (PE) particles from electric cable sheaths as aggregates in mortar and concrete [65].
The mechanical properties of the warp-knitted mesh fabric for protective applications
Published in The Journal of The Textile Institute, 2022
Ping Yang, Hafsa Jamshaid, Pibo Ma
The protective mesh fabric is used in a harsh environment, which is often damaged by external objects, such as sharp sand. Among them, tear propagation damage is the most common failure form. According to Standard Test Method for Tearing Strength of Fabrics by Trapezoid Procedure (ASTM D5587a-2007), the transverse tearing performance of protective warp-knitted mesh fabrics was tested on a universal material testing machine MTS. The preload was 10 N, the cutting sample area was 75 mm × 150mm, the clamping distance of the sample was 35 mm. There were three samples of the same specification which were taken for testing to obtain the average tear performance. For all the specimens, the sampling distance should be greater than 150 mm from the hem. Figure 3(a) is a schematic diagram of the geometric dimensions of the protective warp-knitted mesh fabric. The tearing speed is 100 mm/min.
Experimental study of the effect of processing parameter for prediction of water absorption of the polymer-modified raffia fibre cement mortar
Published in Journal of the Chinese Advanced Materials Society, 2018
R. S. Odera, O. D. Onukwuli, J. T. Nwabanne
The materials used in this research are: Raffia palm fibre (RPF) obtained from Awka, Nigeria. Polyester resin (Darcon type), 2% solution of cobalt nephthalate and 2% solution of methyl-ethy-ketone (MEK) peroxide were used as accelerator and catalyst, polyvinyl alcohol with molecular weight = 14,000, Appearance: dense, white flakes, viscosity of 4% aqueous solution ∼4–6 cps, Ash = max 1% were obtained from Chemical shop in Awka, Nigeria. Dangote 3x cement, 42.5R Grade cement, Portland limestone cement, Nis 444-1:2003-CEM II, B-L42.5R CB-4211 was used for the production of mortar. Very fine sharp sand was obtained from Opi, Nsukka, in Enugu State Nigeria. The sand was dry and free of salt and impurities. The water used was obtained from tap and it was of high quality and free of oils, acids, alkalis, salts, organic materials or other substances that are deleterious to mortar or any metal in the wall.