Properties and hydration behavior of blended clinker and portland-sediment cement pastes

In recent years, an increase of the interest in the use of secondary raw materials (sediment, sludge…) in construction has been observed.  This paper aims to contribute to the use of dredging sediments in the cement industry. Despite the literature on this subject, the available data on the aspects and phenomena related to the hydration process of such mixtures are incomplete. This paper aims to specify the calorimetric curves of hydration of mixtures made, from the sediment trapped at the site of Lyvet in the Brittany region of France. The mixtures are made ??using in one hand clinker and in the other hand Portland cement. Pastes with 8%, 16% and 33% of clinker or Portland cement substituted by sediment are used to determine the hydraulic properties of mixtures. The physico-chemical characterization of materials is made by different techniques to determine the chemical composition and physical properties. X-ray diffraction is used to determine the mineralogical compositions of samples before and after treatment. A  Tian-Calvet microcalorimeter is used to explore hydration behavior of the blended Sediment-Portland cement pastes. The addition of untreated sediment to both clinker or Portland cement increase the dormant period duration. On the contrary, this period becomes shorter when the sediment is thermally treated. The results show that 8% of treated sediment improve hydration of blended Sediment-Portland cement pastes. Mechanical properties of blended sediment-cements are also investigated. After 28 days of curing in water, the mortar containing 8% of treated sediment exhibits a compressive strength equal to 93.7% of the one of the reference mortar, maintaining it in the same cement class (52.5)

Design and Implementation of Wireless Zigbee Sensor Based On Embedded 32-Bits FPGA Processor

Wireless Sensor Networks (WSN) has become an emerging area of research in recent years. Today this wireless sensors are used in many industrial and consumer applications, such as industrial process monitoring and control, machine health monitoring, automotive, home appliance, smart grid applications and so on. In this work, an intelligent wireless sensor system for real time functionality has been suggested. The proposed solution is based on the embedded FPGA design using a new Xilinx MicroBlaze Soft Processor to Increases the performance of the system. The effectiveness of the proposed method is verified by the experimental results. The hardware components include Xilinx FPGA board, XBee Series 2 wireless communication module and end device sensors to capture the physical or environmental quantity, such as temperature, sound or pressure..

Composite cement mortars based on marine sediments and oyster shell powder

International audienceAdditions of dredged marine sediments and oyster shell powder (OS) as cement substitute materials in mortars are examined by several techniques. The sediments have high water and chloride contents and calcite, quartz, illite and kaolinite as principal minerals. The OS powders are entirely composed of calcium carbonate and traces of other impurities. Four mixtures of treated sediments and OS powders at 650 °C and 850 °C are added to Portland cement at 8%, 16% and 33% by weight. The hydration of composite pastes is followed by calorimetric tests, the porosity accessible to water, the bulk density, the permeability to gas, the compressive strength and the accelerated carbonation resistance are measured. In general, the increase of addition amounts reduced the performance of mortars. However, a reduction of gas permeability was observed when the addition was up to 33%. Around 16% of addition, the compressive strength and carbonation resistance were improve

Valorization of glass and shell powders in the synthesis of Belitic clinker

In recent years, waste recycling has become a key issue in construction materials science for achieve the goal of sources of raw materials. The aim of this study is to use waste glass as source of SiO2 oxide and mussel shells consisting essentially of calcium carbonate as starting materials to synthesize belite rich cement. The elaborated clinker is chemically and structurally related to β-Ca2SiO4, by heat solid state activation. After grinding, the raw materials are mixed and heated up to 1050°C. The samples are characterized by X-ray diffraction (XRD) and Fourier Transformed Infrared spectroscopy (FT-IR). The mechanical strength of some sample was measured for 28 and 72 days. The results show the different mineralogical stapes of formation of clinker, the state reaction method allows the elaboration of a cementitious material by a simple heat treatment at relatively low temperature and low release of CO2. The hydration products are also identified by XR diffraction at 2, 7, 28 and 72 days

Valorization of glass and shell powders in the synthesis of Belitic clinker

In recent years, waste recycling has become a key issue in construction materials science for achieve the goal of sources of raw materials. The aim of this study is to use waste glass as source of SiO2 oxide and mussel shells consisting essentially of calcium carbonate as starting materials to synthesize belite rich cement. The elaborated clinker is chemically and structurally related to β-Ca2SiO4, by heat solid state activation. After grinding, the raw materials are mixed and heated up to 1050°C. The samples are characterized by X-ray diffraction (XRD) and Fourier Transformed Infrared spectroscopy (FT-IR). The mechanical strength of some sample was measured for 28 and 72 days. The results show the different mineralogical stapes of formation of clinker, the state reaction method allows the elaboration of a cementitious material by a simple heat treatment at relatively low temperature and low release of CO2. The hydration products are also identified by XR diffraction at 2, 7, 28 and 72 days

Characterization of Moroccan coal waste: valorization in the elaboration of the Portland clinker

Coal exploited in the mine of Jerada (northeast of Morocco) was accompanied by large quantities of waste. The purpose of this work is to characterize this waste with the aim of its use as a material for civil engineering. Mineral and chemical investigations on this waste in the raw state, and at different temperature of heat treatments, were carried out by various methods: X-ray fluorescence, X-ray diffraction, infrared spectroscopy. These analyzes showed that the studied waste, contain essentially a mineral part formed by silica and various clays, as well as coal’s residues. The thermal investigation of waste, by differential scanning calorimetry (DSC), revealed an exothermic phenomenon attributed to the combustion of coal residues. Other phenomena were noted on the thermograms due to the mineral part transformations. In this analysis a comparison was also made with pure coal. These characteristics of coal waste encourage studying its development in reducing energy consumption in the Portland cement manufacture. Mixtures of waste with limestone or with raw cement materials were studied, and the resulting products were analyzed by different methods