The potential to use waste glass, including cathode ray tube (CRT) glass, for making new products or as an admixture to existing ones is being intensively investigated. This kind of research intensified particularly in the period after CRT TV sets and computer monitors were replaced in the market by the advanced technology of thin film transistor (TFT) and liquid crystal display (LCD) screens. Cathode ray tube glass represents a considerable part of electronic waste (e-waste). E-waste globally increases at a far higher rate than other solid waste materials. There is a possibility to recycle cathode ray tube glass and use it in the construction industry. This paper shows the test results of physical and mechanical properties of blocks and paving flags. The reference specimen was made with quartz sand, while the other product employed a combination of quartz sand and ground panel cathode ray tube glass. The glass was ground to the fraction 0.25/1.00 mm, which corresponds to quartz sand fineness. The following tests were performed: shape and dimensions, resistance to freeze/thaw and de-icing salts, water absorption, splitting tensile strength and tensile strength by bending. Special attention was paid to the tests of Böhme wear resistance, slip resistance of the top surface of CRT products using a pendulum, radioactivity and leaching. The texture of the experimental concrete products was observed by SEM (scanning electron microscopy) and analyzed. The results obtained by experimental testing unequivocally show that CRT glass can successfully be used for making concrete blocks and paving flags.

This paper presents the experimental analysis that was conducted on small-scale 1g physical models of piled raft foundation structures with a group of 2 × 2 piles in loose sand. The purpose of the piles was to reduce the settlement of the raft. The test program included twelve experiments, three of which were conducted on a raft alone and nine on piled rafts at pile distances of 3d, 4d, and 5d and pile lengths of 10d, 20d, and 40d, where d is pile diameter. The test results show that the current conventional approach to design of piled raft foundations, at a high safety load factor in piles that assume to take the whole external applied load, is very conservative. Instead, it is more economical to apply a low bearing capacity factor for piles as settlement reducers and maximize use of raft bearing capacity to carry part of the external load.

By its technology, Self-Compacting Concrete does not need compaction by vibration. Compaction of this concrete, in every part, or in every corner of the formwork, including its hardly available parts, is done without any external forces except its own weight. These properties are achieved by adding superplasticizers, commonly with new Viscosity Modification Admixtures, or/and determined amount of powders. It is possible to use different mineral additions, where the use of those which are industrial by - products (like fly ash) has multiple environmental benefits. Lack of natural aggregate in urban areas and increasing distance between deposits of high - quality natural aggregate and building sites, forced building contractors to analyze possibility of replacing of natural aggregate with recycled materials (masonry, slag, concrete, etc.). On the other hand, huge amount of old concrete exists in urban areas and its removal and deposition is a big ecological problem. Aim of this paper is analysis of properties and technology of Self-Compacting Concrete with different mineral additions (lime, fly ash and silica fume), natural and recycled aggregate, considering mixes without recycled aggregate, with third recycled fraction, and with second and third recycled fractions.

In recent years, there has been increasing interest in the use of recycled concrete aggregate (RCA) as a sustainable alternative to natural aggregates in construction. RCA is obtained by crushing and reusing old concrete, which contains both the original aggregate and a cement mortar layer. However, the quality of RCA can vary depending on the characteristics and quantity of the leftover mortar. In this study, we aim to investigate different methods for improving the chemical, physical, and mechanical features of RCA, with a focus on untreated RCA, RCA exposed to a presoaking treatment in HCl, and RCA exposed to rapid carbonation. The overall results show that if RCA is obtained by crushing compact, high-quality concrete, the procedures for improving aggregate quality are not necessary.

The test program was conducted on 1G models capping beams over the tops of the group of 2x2 piles, the purpose of which was to reduce the settlement of the structure. The test program included six experiments, three of which were conducted on capping beams without piles and three on capping beams across the tops of the piles, with pile distances 3d, 4d and 5d, where d is the pile diameter and the pile length is 40 d. Test results show that the current conventional approach to the design of capping beams across the tops of the piles, where the entire load is entrusted to the piles, is too conservative and irrational. Instead, it is more economical to apply a low bearing capacity factor for piles as settlement reducers and maximize use of raft bearing capacity to carry part of the external load.

Flexural strength capacity of the concrete beams depends on different variables such as compressive strength of the concrete, type of the reinforcement used, amount of the reinforcement and cross section of the beam. The flexural strength is expressed as Modulus of Rupture, and it is determined according to ASTM C 293 (center-point-loading). This research is dedicated to investigation of the flexural strength capacity of the concrete beams fabricated using different type of concrete mixtures and different type of reinforcement. The tests presented here were conducted on concrete beams having square cross sections (15cm x 15cm x 1.52m) at Kennesaw State University. Two different types of reinforcement were investigated:  type #4 (13mm) rebar and Greenbar Fiberglass #4 (13mm) rebar along with two different concrete mixture types. Type III cement was used in order to achieve high early strength, and beams were tested to failure when concrete reached prescribed value of 27.6 MPa. In this experimental program load-deflection relationship, load capacity and ductility were the main parameters which were investigated.