Early-age Properties of High-volume Fly Ash Concrete Mixes for Pavement: Volume 2

High-volume fly ash concrete (HVFAC) is more cost-efficient, sustainable, and durable than conventional concrete. This report presents a state-of-the-art review of HVFAC properties and different fly ash characterization methods. The main challenges identified for HVFAC for pavements are its early-age properties such as air entrainment, setting time, and strength gain, which are the focus of this research. Five fly ash sources in Illinois have been repeatedly characterized through x-ray diffraction, x-ray fluorescence, and laser diffraction over time. The fly ash oxide compositions from the same source but different quarterly samples were overall consistent with most variations observed in SO3 and MgO content. The minerals present in various fly ash sources were similar over multiple quarters, with the mineral content varying. The types of carbon present in the fly ash were also characterized through x-ray photoelectron spectroscopy, loss on ignition, and foam index tests. A new computer vision–based digital foam index test was developed to automatically capture and quantify a video of the foam layer for better operator and laboratory reliability. The heat of hydration and setting times of HVFAC mixes for different cement and fly ash sources as well as chemical admixtures were investigated using an isothermal calorimeter. Class C HVFAC mixes had a higher sulfate imbalance than Class F mixes. The addition of chemical admixtures (both PCE- and lignosulfonate-based) delayed the hydration, with the delay higher for the PCE-based admixture. Both micro- and nano-limestone replacement were successful in accelerating the setting times, with nano-limestone being more effective than micro-limestone. A field test section constructed of HVFAC showed the feasibility and importance of using the noncontact ultrasound device to measure the final setting time as well as determine the saw-cutting time. Moreover, field implementation of the maturity method based on wireless thermal sensors demonstrated its viability for early opening strength, and only a few sensors with pavement depth are needed to estimate the field maturity.

High-volume Fly Ash Concrete for Pavements Findings: Volume 1

High-volume fly ash concrete (HVFAC) has improved durability and sustainability properties at a lower cost than conventional concrete, but its early-age properties like strength gain, setting time, and air entrainment can present challenges for application to concrete pavements. This research report helps with the implementation of HVFAC for pavement applications by providing guidelines for HVFAC mix design, testing protocols, and new tools for better quality control of HVFAC properties. Calorimeter tests were performed to evaluate the effects of fly ash sources, cement–fly ash interactions, chemical admixtures, and limestone replacement on the setting times and hydration reaction of HVFAC. To better target the initial air-entraining agent dosage for HVFAC, a calibration curve between air-entraining dosage for achieving 6% air content and fly ash foam index test has been developed. Further, a digital foam index test was developed to make this test more consistent across different labs and operators. For a more rapid prediction of hardened HVFAC properties, such as compressive strength, resistivity, and diffusion coefficient, an oxide-based particle model was developed. An HVFAC field test section was also constructed to demonstrate the implementation of a noncontact ultrasonic device for determining the final set time and ideal time to initiate saw cutting. Additionally, a maturity method was successfully implemented that estimates the in-place compressive strength of HVFAC through wireless thermal sensors. An HVFAC mix design procedure using the tools developed in this project such as the calorimeter test, foam index test, and particle-based model was proposed to assist engineers in implementing HVFAC pavements.

Identification and activity of active compound of bamboo leaves (Bambusa vulgaris Schrad ex.J.C) ethanolic extract against diabetic ulcers gram-negative bacteria from diabetic ulcer’s patient

Background: Bamboo leaves (Bambusa vulgaris Schrad ex.J.C) are plants that are known to have pharmacological activity, one of which is to have antibacterial activity. Diabetic Foot Ulcers (DFU) is one chronic complication of diabetes mellitus. DFU is open sores on the surface of the skin that can be accompanied by local tissue death. Infection that is not appropriately treated in patients can cause amputation. Improper use of antibiotics can cause resistance events. A resistance that occurs in Proteus mirabilis, Pseudomonas aeruginosa, and Escherichia coli in isolates from DFU patients encourages researchers to look for alternative antibiotics from natural resources. Objective: Determine the profile of secondary metabolites by thin-layer chromatography, foam index, total phenols, total flavonoids and the antibacterial activity of bamboo (B. vulgaris) through the antibacterial with clear zone value of bamboo leaf ethanol extract against bacteria E. coli, P. aeruginosa, and P. mirabilis. Method: Phenol, flavonoid, and triterpenoid test using TLC method. Saponin tests were carried out using foam index, fish index, and hemolytic index test methods. Total flavonoid testing using Chang method and total phenol method using the Follin Ciocalteau reagent then proceed using a spectrophotometer. Test the antibacterial activity using the agar diffusion method. Results: Chromatographic profile, phenol, flavonoid, and triterpenoid compounds were obtained; saponin index obtained foam index of 333; fish index of 200; and the hemolytic index of 1,111. The total phenol test was 16.052 ± 3.12 % and the total flavonoid was 2.42 ± 0.44 %. Antibacterial activity test obtained MIC values of 60 mg/ml for E. coli bacteria; 100 mg/ml for the bacterium P. aeruginosa; and 30 mg/ml of P. mirabilis. Conclusion: The content of secondary metabolites found in the ethanol extract of bamboo leaves were flavonoid, phenol, saponin and triterpenoids. Ethanol extract of bamboo leaves has a the potential to produce antibacterial activity against gram-negative pathogenic bacteria isolated from diabetic wound patients Keywords: Bambusa vulgaris Schrad ex.J.C, total phenol, total flavonoid, MIC

The in vitro antisickling effect of purified alkaloids of Cremaspora triflora (Thonn.) K. Schum. (Rubiaceae) and Macaranga schweinfurthii Pax. (Euphorbiaceae)

Introduction and objective: Sickle cell disease is an inherited pathology to an abnormality of hemoglobin precisely hemoglobin S for which there is no curative therapy. It mainly affects sub-Saharan African and Caribbean populations. Thus, this study aims to make the phytochemical screening of Cremaspora triflora and Macaranga schweinfurthii as well as to evaluate the antisickling activity of their purified alkaloids. Methodology: Chemical screening was performed using color and precipitation tests as well as the foam index method. The extraction of the alkaloids was carried out with organic solvents in a basic medium while the purification by open column chromatography. The evaluation of the antisickling activity was carried out by Emmel’s test. Results: The chemical screening highlighted alkaloids, steroids, saponins, tannins, and terpenoids in the species studied. Flavonoids and anthocyanins were present in organs of Macaranga schweinfurthii, but absent in Cremaspora triflora. The extraction showed that Macaranga schweinfurthii leaves contained 0.59% alkaloids and 0.73% alkaloids in Cremaspora triflora leaves. The alkaloids purification allowed to obtain an alkaloidal fraction MS1 (1.24 g, 70.05%) from Macaranga schweinfurthii and two fractions [CT2 (0.934 g, 63.97%) and CT3 (0.006 g, 0.41 %)] from Cremaspora triflora which tested positive with Dragendorff and Wagner reagents. The antisickling activity evaluation showed that the SIR varied between 36.00% (0.25 mg/ml) and 90.66% (1 mg/ml) for the alkaloid solutions of Cremaspora triflora (IC50 of 0.51 mg/ml) as well as between 4.00% (0.25 mg/ml) and 33.33% (1 mg/ml) for the alkaloid solutions of Macaranga schweinfurthii (IC50 of 1.40 mg/ml). Conclusion: This study showed that the purified alkaloids of the studied plant species have an inhibitory power on sickling.

EFFECT OF NONI FRUIT EXTRACT ON THE INTERNAL QUALITY, FOAM INDEX, AND HAUGH UNIT OF THE CHICKEN EGGS

This study aimed to determine the effect of noni fruit extract on the internal quality, foam index, and haugh unit of layers eggs. This research has been carried out at the Chemistry Laboratory of Widya Mandira University Kupang, and the Laboratory of the Faculty of Agriculture, University of Timor, Kefamenanu during February 12, until March 25, 2020. This study used eggs of layer chicken, each treatment using 25 eggs. The method used was a completely randomized design with a one-way pattern consisting of 5 treatments and 5 replications. The treatments given were T0 (control), T1 (2 ml noni fruit extract), T2 (4 ml noni fruit extract), T3 (6 ml noni fruit extract), and T4 (ampicillin). The variables observed were egg weight, air sac diameter, albumen height, egg yolk index, foam leakage, foam index, and Haugh unit. The results of statistical analysis showed the effect of noni fruit extract on egg weight, air sac diameter, foam leakage, foam index, and Haugh unit value. The mean value of each variable showed that the 6 ml (T3) noni extract treatment was better than the other treatments (T0, T1, T2, and T4). It was concluded that to maintain egg quality for up to 21 days, could be preserved with a concentration of 6% noni fruit extract.

Effect of AEA-SP Dosage Sequence on Air Entrainment in FA Concrete

Laboratory measurements show that varying the dosage sequence of air-entraining agent and co-polymer in the mix (SP added before, after or together with AEA) greatly affects air entrainment in fresh and hardened fly ash concrete. Image analysis shows a somewhat lower specific surface when SP is added together with AEA. Foam Index measurements on the same binder materials, admixtures, and dosage sequences were therefore found less useful for studying the effect of admixture combinations. Obtaining a certain air content using the experience with AEA-SP dosage was found to be an untrivial task if there is a lack of parameter control. Finally, examples of successful mixing procedure for air entrainment in a series of high-volume fly ash concrete are shown.

Effect of Surface Active Agent (SAA) on 50/70 Bitumen Foaming Characteristics

To ensure the standard properties of half-warm asphalt (HWA) mixes produced with foamed bitumen, the binder needs to have the best possible characteristics. One way to attain this is to modify the bitumen before it is foamed. The 50/70 penetration bitumen used in this study, was modified with a surface active agent (SAA) at different rates (0.2%, 0.4%, and 0.6% by wt.). The effect of the modifier on the bitumen properties (penetration, softening point, the Fraass breaking point, dynamic viscosity at 60 °C, 90 °C, and 135 °C) and on the binder foaming parameters (expansion ratio - ER, half-life - HL, foam index - FI) was investigated and the optimum quantity of foaming water was determined. Statistical analysis of the results showed that the addition of 0.6% SAA had the most beneficial effect on the set of 50/70 bitumen standard properties and foaming characteristics.

Study on Modified Asphalt Foaming Characteristic Basing on Energy Analysis

Studying on the modified asphalt foaming characteristic, the energy indexes of the actual maximum expansion ratio and the foam index influencing on the modified asphalt foaming effect is analyzed reasonably by varying moisture content. The results show that the half-life of modified foamed asphalt decay sharply with the decrease of SBS content (modified asphalt viscosity),the moisture being mainly applied to modified asphalt foaming is proved with actual max expansion ratio index and evaporated vastly with the decrease of SBS content (modified asphalt viscosity), the modified foamed asphalt stored energy internally is reflected by the foam energy and corrected according to the viscosity.