Behavior of Cementitious Materials under the Effect of an Eco-Cement Based on Dredged Sludge

Abstract

This paper attempts to simulate the use of green materials from the silt in a dam, and reduce the harmful impacts of siltation on Algerian dams affected by frequent droughts and irregular rainfalls, which are resulted from climate change. These harsh weather conditions are the main cause of water erosion in Algeria, leading to a high silting level in many dams across the country. Therefore, it is necessary to dredge the considerable volumes of sludge in the dam areas. This paper treats the sludge dredged from the K’sob dam, and adds the treated sludge into cement, creating a hybrid binder that can be used in composition of cementitious materials. Specifically, the sludge extracted from the K’sob dam was characterized chemically, physically, mineralogically, and mechanically, and introduced both as a substitute of cement and a component in the mixture of ordinary concrete/mortar. The sludge was firstly activated through calcination, and added to cement at the mass dosages of 10%, 15%, and 20% separately. The mechanical behavior, especially that under compression, of cementitious materials (concrete/mortar) based on the treated sludge was studied through lab tests. The test results show that this technical innovation gives the finished product three major properties, namely, high strength, economy, and a beneficial ecological impact. The results obtained are encouraging and promise an optimal exploitation of the sludge from similar dam areas.

Preparation of Green Sustainable Cement Paste Mixture Based on Inorganic Additives: An Experimental and Modelling Approach

“…Influence of ceramic waste powder and PVA on geo-polymers [22] Experimental design, characterization and mechanical tests for different curing temperatures and at different ages Impact of curing temperature of alkaliactivated laterite-rock-powder-based geo-polymer samples [23] Experimental evaluation and characterization of cementbased composites by adding different materials Improvement of thermoelectric properties of large-sized thermoelectric cement composites for surface temperature reduction and pavement energy harvesting [24] Optimization of mechanical and durability properties and characterization of samples with different percentages of materials Enhancement in mechanical properties and durability of high-strength concrete with wheat straw ash as a partial replacement for cement [25] Characterization of the samples by using XRD, SEM, TEM, BET and MIP Study of mortars replaced with waste agriculture waste in the form of aerogel [26] Investigation of the predictive performance of various machine learning models for estimating compressive strength Determination of compressive strength of green concrete with blast furnace slag [27] Mechanical tests of the samples with different dosages of rice straw ash Evaluation of self-compacting concrete with rice straw ash as a partial replacement for cement at different time periods [28] Physical and mechanical testing of the samples containing different percentages of calcined sludge Study of cementitious materials with partial replacement of cement by sludge at different ages [29] A novel ultrasonic treatment using graphene quantum dots (GQDs) significantly improves the dispersion and exfoliation of 2D nanomaterials (GO, CLDH, CN), enhancing their ability to accelerate cement hydration and improve mechanical properties. This method increases the specific surface area and provides more nucleation sites, leading to better cement composite performance [30].…”