Use of Industrial By-Products in Pipeline Concrete Coatings
Proceedings Publication Date
Some of the major problems encountered during pipeline construction are countering buoyancy in hostile wet environments and protecting the pipe in dry environments. A different field condition obligates different protection methodology for the same. Though, several methodologies are used to counter buoyancy, concrete with a density of 2200 to 2400 kg/m3, high strength and durability properties is the perfect material for protecting the pipe and imparting weight. However, production of the constituents of concrete is detrimental to the environment. An environmentally and economically conducive alternate is the use of mineral admixtures as replacements in the cement. Mineral admixtures have been widely and successfully used in building construction projects worldwide and have always bettered their qualities in one way or another. However, their application in pipeline industry is limited. The paper discusses the possibility of the use of such mineral admixtures like fly ash, rice husk ash, blast furnace slag and metakaolin as binary (one admixture with cement) and ternary (two admixtures with cement) replacements in pipeline concrete coatings. The paper presents the results of laboratory experiments for such ternary blended concrete specimens where; the relative proportions for different mixtures were varied to determine the optimum mix proportions. In the investigation, the mixtures were tested to determine the mechanical properties (compressive, flexural and tensile strengths) after 28 days of casting. The use of metallurgical slag based aggregates (instead of natural heavy weight aggregates) is also discussed, thereby entertaining the prospect of imparting strength to the pipe section in addition to weight for countering buoyancy. Being cost effective and environmentally friendly, these replacements could warrant the betterment of not only the overall strength and durability of the pipeline but also the economic viability of such change at a large Scale.