Environmentally Friendly Pervious Concrete for Treating Deicer-Laden Stormwater: Phase I

A graphene oxide-modified pervious concrete was developed by using low-reactivity, high-calcium fly ash as sole binder and chemical activators and other admixtures. The density, void ratio, mechanical strength, infiltration rate, Young’s modulus, freeze-deicer salt scaling, and degradation resistance of this pervious concrete were measured against three control groups. The test results indicate that graphene oxide modified fly ash pervious concrete is comparable to Portland cement pervious concrete. While the addition of 0.03% graphene oxide (by weight of fly ash) noticeably increased the compressive strength, split tensile strength, Young’s modulus, freeze-deicer salt scaling, and degradation resistance of fly ash pervious concrete, it reduced the void ratio and infiltration rate. The fly ash pervious concrete also showed unfavorable high initial loss during the freeze-deicer salt scaling test, which may be attributed to the low hydration degree of fly ash at early age. It is recommended that durability tests for fly ash concrete be performed at a later age

Removal of Boron from aqueous solutions by adsorption using fly ash, zeolite and demineralized lignite

In the present study for the purpose of removal of boron from water by adsorption using adsorbents like fly ash, natural zeolite and demineralized lignite was investigated. Boron in water was removed with fly ash, zeolite and demineralized lignite with different capacities. 94% boron was removed using fly ash. Batch experiments were conducted to test removal capacity, to obtain adsorption isotherms, thermodynamic and kinetic parameters. Boron removal by all adsorbents was affected by pH of solution; maximum adsorption was achieved at pH 10. Adsorption of boron on fly ash was investigated by Langmuir, Freundlich, Dubinin-Radushkevich models. Standard entropy and enthalpy changes of adsorption of boron on fly ash were, =S0 = -0.69 kJ/mol K and =H0 = -215.34 kJ/mol, respectively. The negative value of S0 indicated decreased randomness at the solid/solution interface during the adsorption boron on the fly ash sample. Negative values of H0 showed the exothermic nature of the process. The negative values of G0 implied that the adsorption of boron on fly ash samples was spontaneous. Adsorption of boron on fly ash occurred with a pseudo-second order kinetic model, intraparticle diffusion of boron species had also some effect in adsorption kinetics

Self-machinery?: steel trusses and the management of ruptures in eighteenth-century Europe

Abstract: Effectiveness Of Rice Husk Ash And Poly Aluminum Chloride In Reducing Exposure Colour Liquid Waste Industry Sasirangan. Sasirangan fabric industry is the textile of industry in Kalimantan Selatan produce wastewater of dyeing cloth sasirangan process that uses water as a primary adjuvant in stage process.The study aims to determine the effectiveness of rice husk ash and Poly Aluminium Chloridereduce levels of dyes in wastewater sasirangan "Oriens Handycraft". This study tested a laboratory scale with dose variation of rice husk ash and Poly Aluminium Chloride for reduced levels of dyes in wastewater sasirangan. The study design is a randomized pretest - posttest control group design. The population of the waste liquid fabric manufacturesasirangan results and samples are the waste from the manufacture of cloth sasirangan which represents the population. This study conduct statistical tests usingKruskal Wallis and Mann-Whitney Test.Theresultsofthestudyof color levels priorto treatment equal to 2,712 PtCo and after treatment ranges from 676.3 to 978.7 PtCo at a dose of 58 grams of rice husk ash; 59 g; 60 g; 61 g; 62 gr and Poly Aluminium Chloride 0.5 gr. For a dose of 58 grams of rice husk ash; 59 g; 60 g; 61 g; 62 gr and Poly Aluminium Chloride 1 g of color levels before treatment and after PtCo 1775 amounted to 227.7 PtCo ranges up to 240 PtCo. Rice husk ash and Poly Aluminium Chloride effective at pH 6.5 - 7. Results of normality test showed abnormal data. Kruskal Wallis test probability value 0.002 <0.05, there is a difference between the average dosing in the control group and the treatment group and the Mann-Whitney Test probability value of 0.009 (0.018 <0.05), the rice husk ash dosing and Poly Aluminium Chloride 1 g more effective than rice husk ash dosing and Poly Aluminium Chloride 0.5 g.Efforts government can do is provide the appropriate policy on effluent quality standards and attention to industrial waste disposal sasirangan. For the industry can manage its waste before waste into the environment. Keywords: SasiranganWaste; Materials coagulant; pH; Dye

Evaluation of Fly Ash Concrete Durability Containing Class II Durability Aggregates, July 1986

Fly ash was used in this evaluation study to replace 15% of the cement in Class C-3 concrete paving mixes. One Class "c" ash from Iowa approved sources was examined in each mix. Substitution rate was based on 1 to 1 basis, for each pound of cement removed 1.0 pound of ash was added. The freeze/thaw durability of the concrete studied was not adversely affected by the presence of fly ash. This study reveals that the durability of the concrete test specimens made with Class II durability aggregates was slightly increased in all cases by the substitution of cement with 15% Class "c" fly ash. In all cases durability factors either remained the same or slightly improved except for one case where the durability factor decreased from 36 to 34. The expansion decreased in all cases

Environmentally Friendly Pervious Concrete for Treating Deicer-Laden Stormwater: Phase II

In Phase I of this project, graphene oxide (GO)-modified pervious concrete was developed using coal fly ash as the sole binder. The primary objectives of Phase II of this project were (1) to evaluate the stormwater infiltration capacity of GO-modified fly ash pervious concrete; (2) to evaluate the durability performance of GO-modified fly ash pervious concrete using freeze/thaw and salt resistance testing methods; and (3) to use advanced analytical tools to fully characterize the GO-modified fly ash binder. Test results indicate different degrees of reduction in concentrations of possible pollutants in stormwater—copper, zinc, sulphate, chloride, ammonia, nitrate, and total phosphate. The incorporation of GO significantly improved the resistance of pervious concrete to freeze/thaw cycles and ambient-temperature salt attack. The specimens were examined using X-ray diffraction, which revealed that the mineralogy and the chemical composition of fly ash pastes differ considerably from those of cement pastes. Nuclear magnetic resonance was used to study the chemical structure and ordering of different hydrates, and provided enhanced understanding of the freeze/thaw and salt scaling resistance of fly ash pervious concrete and the role of GO

Water absorption and salt attack resistance of coal ash brick made of different percentage of foam content

Coal ash which constitute of fly ash and bottom ash were proved to be used as main component in brick production. However, published work on the coal ash brick with addition of foam in order to produce lightweight brick is still lacking. This thesis reports the effect of variation in foam content in coal ash brick on the density, water absorption and salt attack resistance. Comparison of those parameters was made between the coal ash bricks and conventional brick. The coal ash brick mixes were formulated using industrial by-product, ground granulated blastfurnace slag (GGBS) which is activated with an alkaline (hydrated lime or Portland cement) combined with coal ash from coal-fired thermal power plant. The blended binder comprising of hydrated lime (HL) – GGBS and Portland cement (PC) –GGBS were used to stabilize the coal ash brick. Foam was used to produce lightweight brick. The percentage of foam added to the brick mixes are 25%, 50% and 75%. A total of sixty (60) brick specimen subjected to ten (10) series of mix proportion were cast and put in air curing condition for at least 28 days before testing. The density measurement in accordance with AS/NZS 4456.8, water absorption test in accordance with BS EN 772-21 and salt attack resistance in accordance with AS/NZS 4456.10 were evaluated on the brick specimens. The results indicated that the density of coal ash brick decreases with the increase in foam content. Also for bricks composed of both blended binder, the water absorption were directly proportional to the amount of foam. Thus, the water absorption of foam brick increases with the reduction in density. Higher foam content leads increase of pores and capillaries in brick structure, therefore the brick become weaker to resist on salt attack. XRD pattern of formed brick with 75% of foam addition on HL-GGBS coal ash brick portrays ettringite formation were attributed to disruption of brick structure. The use of coal ash with HL–GGBS and PC-GGBS combination as binder agent has been observed to be lightweight, low in water absorption, and advantageous in protection to salt attack compare to the conventional brick. The optimum proportion respected to the foam content is 50% in balance condition with approximately 1-2% of mass loss due to salt attack, 12-13% of water absorption and density significantly reduced to 1600kg/m3 . Keywords – fly ash; bottom ash; hydrated lime; Portland cement; ground granulated blastfurnace slag (GGBS); foam; brick; density; water absorption; salt attack resistanc

The effect of variations of cese waste waste levels on marshall parameters in Ac-Wc layer

In the asphalt pavement mixture, filler is needed to support the performance of the pavement construction in order to withstand traffic loads. Various types of fillers have been widely used, including rock ash, portland cement and others. However, the limitation of natural resources encourages the use of waste materials in the construction of road pavements, a potential for the production of bagasse. In this study, sugar cane waste was used as a filler in the asphalt pavement mixture. The research method used is an experimental method, where the experiment is carried out to obtain a data set and analysis of test results. The test was carried out in 2 stages, namely testing the test object with Portland cement filler which was carried out to obtain Marshall parameters and KAO values and testing of the test object with bagasse ash filler to produce Marshall parameters and optimum filler content values. The results showed that the use of bagasse ash waste with a proportion of 5% to the weight of the filler increased stability. Tests carried out on the AC-WC layer mixture obtained the KAO value of 5.7% and the optimum filler content of 5.5%. The stability value with 7% bagasse ash filler obtained 1237.1 kg by immersing the test object for 30 minutes and 1156.4 kg with 7% bagasse ash filler by soaking the test object for 24 hours at 60 ° C, meeting the minimum requirements of 800 kg

Sediment disturbance caused by a suspension-feeding tubular agglutinated foraminifer

We report the occurrence of in-situ sediment disturbance caused by a specimen of Rhabdammina observed in life position on the 1991 Mt. Pinatubo ash layer in the abyssal South China Sea. The specimen extracts sediment grains from the ash layer to build its agglutinated test, causing a depression, or “moat” to form around the base of the specimen. We suspect that such fine-scale disturbance caused by large, erect tubular foraminifera is a common feature of the fossil record in deep-sea settings