Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. High volume fly ash (HVFA) mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash

Penggunaan Bottom Ash Sebagai Pengganti Agregat Halus Pada Mortar Hvfa

Bottom ash adalah material limbah PLTU yang melimpah dan kurang dimanfaatkan. Terdapat potensi pemanfaatan bottom ash sebagai agregat halus dalam campuran beton. Dalam penelitian ini, bottom ash diberi treatment ayak dan tumbuk untuk digunakan sebagai pengganti pasir dalam campuran beton. Hal pertama yang dilakukan adalah pengujian karateristik fisik dan kimiawi dari bottom ash. Dilakukan pengujian water content, sieve analysis, fineness modulus, dan berat isi dari pasir dan bottom ash yang digunakan. Pengujian kuat tekan dan flowability pada mortar high volume fly ash (HVFA) menggunakan bottom ash sesudah diberi treatment dibandingkan dengan mortar HVFA yang menggunakan pasir. Pengujian tersebut dijadikan tolak ukur untuk mengevaluasi pengaruh penggantian bottom ash terhadap pasir. Dari penelitian ini, dapat dievaluasi bahwa Perubahan kekuatan dan flowability dari mortar dengan 100% penggantian pasir dengan bottom ash bervariasi. Bottom ash yang diayak dengan halus memberikan penurunan kekuatan dan flowability terbanyak, sedangkan bottom ash yang ditumbuk memberikan hasil yang bertolak belakang

The character of PA3235 virulence factors of Pseudomonas aeruginosa PAO1 – a preliminary study

Introduction:Many virulence factors ofPseudomonas aeruginosaPAO1 are regulated by temperature and host conditions upon infection. Based on microarray data, the PA3235 gene is one of the upregulated genes during cell growth at 37 °C. Until now, no information about its role in PAO1 pathogenicity.Methods:The PAO1∆PA3235 strain was constructed by overlapping polymerase chain reaction (PCR) method and through biparental mating. The deletion was confirmed by PCR and restriction analyses. The virulence factors of bothP. aeruginosa PAO1 wild type and ∆PA3235 mutant strains were examined, which consisted of the amount of pyocyanin and pyoverdine, swarming, swimming, and twitching motility, biofilm formation, 3-oxo-dodecanoyl-homoserine lactone concentration, and growth curve profile. Data were analyzed using Student’s t-tests to determine differences between treatments. P-value < 0.05 were considered significant.Results:The ∆PA3235 strain was successfully constructed. At 37 ºC, the mutant produced less pyocyanin (p-value 0.0004), pyoverdine (p-value 0.0009), and swarm area than the wild-type. The dendrites pattern of both strains was similar. The mutant and parental strains showed no differences in swimming and twitching motility when incubated at 22 ºC and 37 ºC. The mutant produced more biofilm compared to the wild-type strain (p-value 0.0013). The AHL was higher in the mutant than in wild type strain (p-value 0.0095) after 24 h incubation. Both the wild type and mutant strains exhibited similar growth patterns in LB broth. The mutant colonies also showed the same morphology as the wild type on the LB plate (not shown here).Conclusion:The deletion of the PA3235 gene from thePseudomonas aeruginosagenome caused some changes in virulence factors production, as the bacterium grew at body temperature 37°C. We predicted that the PA3235 gene might function to transport molecules involved in the early infection of this bacterium to human

Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. Highvolume fly ash (HVFA) mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash

Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. Highvolume fly ash (HVFA) mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash