EFFECT OF QUANTITY OF SILICA FUME ON THE COEFFICIENTS OF CONSTRUCTIVE QUALITY FINE-GRAINED CONCRETE AND STRUCTURAL FOAM CONCRETE

The article presents the coefficients of the constructive quality of fine-grained concrete and structural foam concrete with different percentages of micro-silica in the mixture.

Resource-Saving Technologies in the Thermal Insulation-Structural Foam Glass Production

The modern building materials market places high demands on heat-insulating and heat-insulating structural materials. In this connection, the issues of developing high-quality building materials obtained on the resource-saving technologies basis allowing to solve two interrelated problems are topical. The first problem is the industrial waste generated and existing stocks disposal. The second is associated with a decrease in the traditional raw materials deficit [1]. These problems solution, combining rational technological solutions, is based on the scientific research achievements in this area, in particular in the foam glass production. The priority scientific research areas in the foam glass materials production are the developments related to the study, the new raw materials use and the production of foam glass mixture compositions on their basis, which provide, along with the necessary performance properties, high environmental safety requirements [2, 3].

Investigation of Flame Retardant rPET Foam

The use of plastics in the food and the packaging industries continuously is increasing. In these areas of use the product’s life cycle is short, therefore it quickly turns into waste. The polyethylene terephthalate (PET) - the material that is used as beverage containers - are the material with the greatest environmental load. The physical recycling of PET bottles in large quantities was the research goal. During the work with the help of chemical foaming a closed cell structural foam from PET bottle was produced. The research was carried out with upcycling using chain extender and impact modifier additives. For industrial use a bromine-based flame retardant was used and excellent flame retardancy was achieved. Based on the results obtained, the material previously managed as waste, with the appropriate treatment can be involved into the manufacturing of new products.

Design and Manufacturing of Tendon-Driven Soft Foam Robots

SummaryA design and manufacturing method is described for creating a motor tendon–actuated soft foam robot. The method uses a castable, light, and easily compressible open-cell polyurethane foam, producing a structure capable of large (~70% strain) deformations while requiring low torques to operate (<0.2 N·m). The soft robot can change shape, by compressing and folding, allowing for complex locomotion with only two actuators. Achievable motions include forward locomotion at 13 mm/s (4.3% of body length per second), turning at 9◦/s, and end-over-end flipping. Hard components, such as motors, are loosely sutured into cavities after molding. This reduces unwanted stiffening of the soft body. This work is the first demonstration of a soft open-cell foam robot locomoting with motor tendon actuators. The manufacturing method is rapid (~30 min per mold), inexpensive (under $3 per robot for the structural foam), and flexible, and will allow a variety of soft foam robotic devices to be produced.

Compression of structural foam materials – Experimental and numerical assessment of test procedure and specimen size effects

This study was initiated based on the observation that standardized test methods for flatwise compression of foam materials, give significantly different test results for the measured moduli, and that these standards to date lack adequate instructions on how the strain should be measured and what specimen size should be used. A brief review of previous work shows that existing test methodologies provide significantly different results for the compressive moduli of foams depending on how the strains are measured. A thorough experimental study of the out-of-plane compressive properties is conducted on three different closed-cell foam materials, where strains measured with two different extensometer placements, and with digital image correlation, come out significantly differently. A parametric study is also performed showing that the results vary considerably with in-plane specimen dimensions, indicating effects of finite size and localized strain at edges. Both stochastic amorphous and homogenized finite element models of foam back the experimental observations by illustrating the effects of finite size and various boundary conditions on the measured properties.