Substitution of Fly Ash as Mineral Filler in Wearing Course of Hot Mix Asphalt

Fly Ash (FA) is one of the sustainable materials to substitute Ordinary Portland Cement (OPC) was found commercialized in construction field but the usage in HMA pavement is limited. Thus, this study is important to promote FA as a sustainable filler instead of using OPC to reduce greenhouse gases. The primary aim is to investigate the Marshall Stability of HMA that incorporating of OPC and FA as filler. In addition, Optimum Bitumen Content (OBC) determination also conducted in this study. Marshall Stability test was conducted based on ASTM 2006 for both mixtures. The parameters gained from the test are the stability, flow, air void in mix (VIM), void filled bitumen (VFB) and stiffness being used to OBC. The OBC for HMA with OPC filler obtained is 5.06% meanwhile for HMA with FA is 4.79%. All Marshall Parameters was complied with of Malaysia Public Work Department (PWD) Standard for both mixtures. The HMA with FA filler give better results for all parameters. Based on OBC percentage, usage of asphalt binder was reduced at 0.29%. Thus, it was more economical if using FA compared with OPC as a filler. Furthermore, HMA with FA filler have better stability and strength as well as lesser deformation with HMA with OPC filler. For the overall, FA have huge potential in substituting other mineral filler to produce better quality of asphalt pavement.

Composite Material for the Manufacture of Plastic Sleepers

The composite materials intended for the manufacture of plastic sleepers were produced, which significantly differ from the materials widely used in railway transport of wooden and reinforced concrete sleepers. The coefficients of linear thermal expansion of the obtained materials are significantly lower. Polyvinyl chloride is used as a polymer binder, and the filler is a mixture of softwood flour with the mineral filler in the form of finely ground chalk. It was shown that by varying the content of the components of the composite, a change in its density is achieved by 19%, and the change in the value of the coefficient of linear thermal expansion depends on the temperature and relaxation of internal stresses in the samples, varying by 18.7 times – from 288.4·10-6 to 15.4·10-6 °C -1.

SPECIFIC FEATURES OF THE FORMATION OF THE MICROSTRUCTURE OF GRANULAR AGGREGATES ON DIFFERENT BINDING COMPOSITIONS (PART 2)

This article is a continuation of the previous research. It includes analysis of the formation of the structure of granular aggregates during the hydration of the binder composition of BC-2 (PC 500-D0-N + 20 % quartz sand), prepared in a jet vortex mill. The study reveals the features of the dispersion of the quartz mineral filler (fractions ≤0.16; ≤0.315; ≤0.63 mm) and the main patterns of influence on structure formation at hydration of binders, differing in the composition and dispersion of particles. The paper analyzes physical and mechanical tests of the samples with the best strength characteristics and studies the features of their microstructures. The study of the microstructures of the samples reveals regularities, consisting in the formation of crystalline phases of different densities. It is noted that the introduction of 20 % mineral finely dispersed filler into PC 500-D0-N, in the form of quartz sand, ensures the formation of dense sub-microcrystalline hydrate phases when using a filler fraction ≤0.63 mm, which contributes to an increase in the additional strength of the samples by more than 20 %. It has been found that the mineral filler plays the role of crystallization centers, binding individual grains of fillers and sealing general structure of the composite. More compact healing of the pore space has been established for the composite with small crystalline new formations of hydrated calcium silicate

Development and Analysis of the Physicochemical and Mechanical Properties of Diorite-Reinforced Epoxy Composites

The aim of this paper is to study the effect of a polyfunctional modifier oligo (resorcinol phenyl phosphate) with terminal phenyl groups and a dispersed mineral filler, diorite, on the physicochemical and deformation-strength properties of epoxy-based composites. The efficiency of using diorite as an active filler of an epoxy polymer, ensuring an increase in strength and a change in the physicochemical properties of epoxy composites, has been proven. We selected the optimal content of diorite both as a structuring additive and as a filler in the composition of the epoxy composite (0.1 and 50 parts by mass), at which diorite reinforces the epoxy composite. It has been found that the addition of diorite into the epoxy composite results in an increase in the Vicat heat resistance from 132 to 140–188 °C and increases the thermal stability of the epoxy composite, which is observed in a shift of the initial destruction temperature to higher temperatures. Furthermore, during the thermal destruction of the composite, the yield of carbonized structures increases (from 54 to 70–77% of the mass), preventing the release of volatile pyrolysis products into the gas phase, which leads to a decrease in the flammability of the epoxy composite. The efficiency of the functionalization of the diorite surface with APTES has been proven, which ensures chemical interaction at the polymer matrix/filler interface and also prevents the aggregation of diorite particles, which, in general, provides an increase in the strength characteristics of epoxy-based composite materials by 10–48%.