Evaluating Prediction Models of Creep and Drying Shrinkage of Self-Consolidating Concrete Containing Supplementary Cementitious Materials/Fillers

Supplementary cementitious materials (SCMs) and fillers play an important role in enhancing the mechanical properties and durability of concrete. SCMs and fillers are commonly used in self-consolidating concrete (SCC) mixtures to also enhance their rheological properties. However, these additives could have significant effects on the viscoelastic properties of concrete. Existing models for predicting creep and drying shrinkage of concrete do not consider the effect of SCM/filler on the predicted values. This study evaluates existing creep and drying shrinkage models, including AASHTO LRFD, ACI209, CEB-FIP MC90-99, B3, and GL2000, for SCC mixtures with different SCMs/fillers. Forty SCC mixtures were proportioned for different cast-in-place bridge components and tested for drying shrinkage. A set of eight SCC mixtures with the highest paste content was tested for creep. Shrinkage and creep test results indicated that AASHTO LRFD provides better creep prediction than the other models for SCC with different SCMs/fillers. Although all models underestimate drying shrinkage of SCC with different SCMs/fillers, the GL2000, CEB-FIP MC90-99, and ACI 209 models provide better prediction than AASHTO LRFD and B3 models. Additionally, SCC mixtures with limestone powder filler exhibited the highest creep, while those with class C fly ash exhibited the highest drying shrinkage.

Effectiveness of Catching Free Radicals in Cigarette Smoke with Biofilters Made from Bidara Leaf Powder

<p class="JIPIAbstrakKeywords">A number of diseases have been stigmatized as a side effect of smoking and its smoke. Reducing the dangers of smoking by capturing radioactive substances from cigarette smoke is one way to reduce or reduce the level of danger. This study aims to make a filter made from bidara leaf powder to bind free radicals in cigarette smoke. Bidara leaf powder with PEG solution was mixed and stirred until homogeneous with variations in the mass of bidara powder 0.7 grams, 0.8 grams, 0.8 grams, 0.9 grams and 1 gram. The product was molded with a 0.7 cm diameter pipe hose, allowed to dry before being removed from the mold, and heated at a temperature of 105^o C for 20 minutes. Biofilter matrix using polyethylene glycol (PEG) and egg white, bidara leaf powder as a biofilter filler. The physical characteristics of the membrane were obtained by conducting density and porosity tests with SEM. The effectiveness of the biofilter membrane is known by passing cigarette smoke, then the number of free radicals trapped in the biofilter is analyzed using ESR. The results showed that the use of a biofilter made from bidara leaf powder with a mass of 0.9 grams with an egg white matrix was able to bind 85.7% of free radicals (C, O₂^-, C, Peroxy, CO₂^-, and Hydroperoxides) with 100% effectiveness, density. 0.893 g/cm³ and porosity 0.6788%. Testing the characteristics of the biofilter with SEM (Scanning Electron Microscopy) shows the size of the biofilter pores between 2-3 m, while the size of free radicals in cigarette smoke ranges from 20-430 nm. This indicates that the ability to bind free radicals in cigarette smoke is influenced by the antioxidant activity of bidara leaf powder (filler biofilter).</p>

PRODUCTION OF FIBER AS AN INPUT MATERIAL FOR THE 3D PRINTING PROCESS

Additive manufacturing, also known as 3D printing, is the process of joining organic, ceramic, polymer, metal and others materials. Most often used as input material are the ABS and PLA plastics. A large number of plastic products is constantly generated by industry, which beckons the idea how to manufacture these products in more environmentally friendly way. This paper deals with the possibility of producing a 3D printing fiber from a granular PLA material Ingeo 2003D with the addition of a mixture of color powder pigment and fiber from the selected PLA material with a glass powder filler. The production was carried out using the FilaFab PRO EX350 device, which is designed for fiber extrusion for 3D printing technology. The aim of the experiment was the creation of new materials in the form of fibers and their mutual comparison in tensile tests with commercially available materials intended for 3D printing.

Research of Hardness of Polymer Composite Materials Based on Silicone and Aluminium Hydroxide with Various Mechanical-Chemical Processing

Polymer composites are one of the types of modern functional materials. This class includes many different in structure and field of application materials, including dispersed-filled polymer composites [1]. Such materials are made by mixing a polymer matrix in a fluid state with a powder filler and then curing. The properties of the resulting materials are influenced by a variety of factors, including the nature of the preliminary (prior to addition to the mixture with the polymer) mechanical-chemical processing of the filler.

Dynamic Mechanical Analysis of Bio-Based and Synthetic Petroleum Based Polymer Foams with Powder Type Organic Filler at Prolonged Ultra-Violet Exposure

Wood powder filler applied to the bio-based and epoxy polymer foams has the potential to reinforce the polymer foam structure. The 'Meranti' wood filler type was used as the filler in this analysis. In order to observe the pore size of each sample when exposed to different hours of UV exposure using optical microscopy (OM), this study was made.This analysis was conducted to compare the mechanical properties of each sample with different filler ratios of 0 wt%, 5 wt%, 10 wt%, 15wt% and 20 wt% at different UV exposure hours, which is 0 hour to 6000 hours with a 2000 hour rapid increase. Using the DMA Q800 TA unit, the mechanical properties were studied. In order to obtain the product of their mechanical properties, samples having a scale of 40 x 10 x 5 mm were clamped into the machine. The results will show the value of tan δ, loss modulus and storage modulus from the DMA test.The tan δ value shows that the high tanδvalue will be produced by the higher ratio filler. In contrast to bio-based polymer foams, epoxy polymer foams with powder fillers have the highest tan δ value. It shows that the higher filler ratio can be reported with the lower tan δ value. As the filler ratio filler in the polymer foams increased, the consequence of storage and loss modulus was found to increase. The greater the modulus of loss and the modulus of storage, the lower the temperature. As energy is lost as heat during UV irradiation exposure, bio-based polymer foams with a high powder filler ratio can dissipate more energy.