KINETICS OF THE CORROSION PROCESS OF HOT DIP GALVANIZED STEEL REINFOCEMENT IN FRESH CONCRETE

The quality of concrete structures is largely reflected by its durability. According to literature, the rebar corrosion initiation is delayed and the life duration of concrete structures reinforced with hot dip galvanized rebar is extended with up to 70 years compared to life duration of concrete structures reinforced with non-galvanized steel rebar. It is well known that the galvanized rebar surface activates in contact with the alkaline environment of fresh concrete, forming a crystalline compound namely calcium hydroxizincate. This crystalline compound is important for the kinetic and corrosion mechanism of rebar embedded in concrete. This work aims to evidence the galvanized rebar corrosion kinetics in fresh concrete, during the concrete hardening. Electrochemical methods were used during experiments. The test results show an activation of the zinc layer of galvanized rebar in contact with the alkaline environment of concrete, during the first days after rebar embedding in concrete. Zinc corrosion products formation lead to better corrosion resistance of galvanized steel rebar, compared to the resistance of non-galvanized steel rebar

QUALITATIVE ANALYSIS OF FILTERS FOR THE MECHANICAL NANOFILTRATION OF HOUSEHOLD DRINKING WATER

The research carried out in this paper aimed to identify and compare the mechanical filtration capacity of the existing nanoparticles, correlated with the electro-chemical properties of the drinking water provided to the household users through the public network of Cluj-Napoca. The tested filters are available to the general public and the results of the research provide both the certainty of the importance of using drinking water filters, but also the prospect of purchasing an optimal relation quality - price filter based on the needs of the domestic users. The qualitative analysis of the tested filters was carried out by laboratory testing of a representative sample of drinking water filters that once reached the maximum lifetime, were cut and subjected to microscopic analysis using an Atomic force microscope (AFM). The microscopic analysis aimed to determine the filtration capacity by identifying the size and agglomeration density of the nanoparticles retained by mechanical filtration

NATURAL FIBRE COMPOSITE PANELS FOR THERMAL INSULATION OF BUILDINGS: A REVIEW

In the conditions of integration of Romania in the European Union, a profitable and modern agriculture is one of the main conditions for having a competitive economy. That is why, the management of agricultural farms, no matter what their size, is very important in achieving this goal. The paper presents studies and researches made on farm processing machinery management, which is a very important step in a good farm management. We analysed the measures processing operations which are required before the crop may be fed or stored, especially reducing machinery and drying machinery. In what concerns the reducing machinery, we have presented all the types of these machines with their particular characteristics and advantages. We also analysed their mechanisms and the possible adjustments that can be made and presented the importance of drying machines in the final result of farm management and have found the time limits for safe storage of shelled corn

THERMAL BEHAVIOUR OF POLYURETHANE MATRIX COMPOSITE MATERIALS

This paper describes the thermal behaviour of some composite materials, polyurethane foams reinforced with tire rubber waste and fir sawdust. According to experimental results, TG and DTG plots were drawn for finding the thermal stability domains, the partial and total weight loss and the temperature of the maximum weight loss. Composite materials have superior thermal stability of raw materials from which they were made. Increasing the percentage of polyurethane foam results in greater weight loss front of recycled rubber, but lower than fir sawdust and polyurethane foam

TRIZ Model Used for Complaint Management in the Automotive Product Development Process

AbstractThis paper presents a new method of using TRIZ methodology for the validation of the corrective permanent action during complaints in completion of the 8D Report in the automotive industry. This article focuses on complaints which appear in the development phase. If during the production, specific methodologies regarding the complaints management for control and analysis are defined, then in the development phase these become more sensitive. Therefore a new method of using TRIZ in validation of the corrective permanent actions, before being implemented on the product, is proposed