We examined the applicability of the pumice aggregate on the concrete formed by considering the reactive powder concrete mixture ratios, for the rigid superstructure concrete road pavement and building construction. T...We examined the applicability of the pumice aggregate on the concrete formed by considering the reactive powder concrete mixture ratios, for the rigid superstructure concrete road pavement and building construction. The natural pumice aggregate in fibrous and non-fibrous concrete samples was used in the production of concrete by fracturing in 0.1-0.6 mm dimensions in rotor mill. The concreted formed in this way is named after the pumice powder concrete(PPC). The PPC samples produced were taken 7 days as 20 ℃ standard water cure, 28 days as 20 ℃ standard cure and 9 different types of combined cures. The combined cures were applied different temperatures in different durations. PPC samples were subjected to some pressure and flexural tests at the end of the standard water and combined cures. The highest compressive and flexural strengths of PPC samples were obtained after the combined cures: 3 days in 20 ℃ as standard water curing + 2 days in 180 ℃ in drying-oven. The highest compressive strength of PPC samples without any fiber was found to be 47.27 MPa, as for the highest flexural strength, it is found to be 5.23 MPa, in the end of the study. The highest compressive strength of fibrous PPC samples was 51.12 MPa, while flexural strength was 6.57 MPa.展开更多
The main objective of this experimental study is to investigate the behavior of Recycled Reactive Powder Concrete (RRPC) developed from finely dispersed local waste raw materials. In this study, RRPC was developed by ...The main objective of this experimental study is to investigate the behavior of Recycled Reactive Powder Concrete (RRPC) developed from finely dispersed local waste raw materials. In this study, RRPC was developed by utilizing local wastes (finely dispersed waste glass powder, waste fly ash and waste ceramic powder) together with Portland cement, fine sand, admixture, steel fibers and water through full replacement of silica fume as well as quartz powder for sustainable construction practice. In this study, all raw materials for making RRPC were analyzed for X-Ray Fluorescence analysis. For sustainability of local construction works, this study employed standard curing method at ambient temperatures instead of steam curing at higher temperatures. Moreover, hand mixing was used throughout the study. To evaluate the structural performances of the developed RRPC mixes, compressive and flexural strengths of RRPC were investigated experimentally and compared with the control mix. The experimental results indicated that replacing the silica fume fully by finely dispersed local waste glass powder (GP) and fly ash (FA) is a promising approach for local structural construction applications. Accordingly, a mean compressive strength of 62.9 MPa and flexural strength of 8.8 MPa were developed using 50% GP-50% FA at 28thdays standard curing. In this study, 17.56% larger compressive strength and 30.6% flexural strength improvements were observed as compared to the control mix.展开更多
Composition, morphology, and structure of hydration products in hardened pastes of three kinds of blended cement（cement-silica fume, cement-quartz powder and cement-silica fume-quartz powder） hydrated under differen...Composition, morphology, and structure of hydration products in hardened pastes of three kinds of blended cement（cement-silica fume, cement-quartz powder and cement-silica fume-quartz powder） hydrated under different curing regimes（standard curing, 90 ℃ steam curing, 200 ℃ and 250 ℃ autoclave curing） were investigated by X-ray diffraction and field emission scanning electron microscope equipped with EDAX system. Results showed that the main hydration products in three kinds of hardened pastes under standard curing condition are all C-S-H gels, CH, and AFt. Under 90 ℃ steam curing condition, the main hydration products of cement-silica fume and cement-silica fume-quartz powder are C-S-H gels, whereas those of cement-quartz powder are C-S-H and CH. Under 200 or 250 ℃ autoclave curing condition, no obvious crystallized CH phase is found in hardened pastes of three kinds of blended cement, and C-S-H gels are transformed into one or more crystalline phases such as tobermorite, jennite, and xonotlite. The chemical composition and morphology of these crystalline phases depend on the composition of mixture and autoclave temperature.展开更多
基金Funded by the Scientific Research Projects Department of Bitlis Eren University(No.BEBAP-2016.07)
文摘We examined the applicability of the pumice aggregate on the concrete formed by considering the reactive powder concrete mixture ratios, for the rigid superstructure concrete road pavement and building construction. The natural pumice aggregate in fibrous and non-fibrous concrete samples was used in the production of concrete by fracturing in 0.1-0.6 mm dimensions in rotor mill. The concreted formed in this way is named after the pumice powder concrete(PPC). The PPC samples produced were taken 7 days as 20 ℃ standard water cure, 28 days as 20 ℃ standard cure and 9 different types of combined cures. The combined cures were applied different temperatures in different durations. PPC samples were subjected to some pressure and flexural tests at the end of the standard water and combined cures. The highest compressive and flexural strengths of PPC samples were obtained after the combined cures: 3 days in 20 ℃ as standard water curing + 2 days in 180 ℃ in drying-oven. The highest compressive strength of PPC samples without any fiber was found to be 47.27 MPa, as for the highest flexural strength, it is found to be 5.23 MPa, in the end of the study. The highest compressive strength of fibrous PPC samples was 51.12 MPa, while flexural strength was 6.57 MPa.
文摘The main objective of this experimental study is to investigate the behavior of Recycled Reactive Powder Concrete (RRPC) developed from finely dispersed local waste raw materials. In this study, RRPC was developed by utilizing local wastes (finely dispersed waste glass powder, waste fly ash and waste ceramic powder) together with Portland cement, fine sand, admixture, steel fibers and water through full replacement of silica fume as well as quartz powder for sustainable construction practice. In this study, all raw materials for making RRPC were analyzed for X-Ray Fluorescence analysis. For sustainability of local construction works, this study employed standard curing method at ambient temperatures instead of steam curing at higher temperatures. Moreover, hand mixing was used throughout the study. To evaluate the structural performances of the developed RRPC mixes, compressive and flexural strengths of RRPC were investigated experimentally and compared with the control mix. The experimental results indicated that replacing the silica fume fully by finely dispersed local waste glass powder (GP) and fly ash (FA) is a promising approach for local structural construction applications. Accordingly, a mean compressive strength of 62.9 MPa and flexural strength of 8.8 MPa were developed using 50% GP-50% FA at 28thdays standard curing. In this study, 17.56% larger compressive strength and 30.6% flexural strength improvements were observed as compared to the control mix.
基金Funded by the National Natural Science Foundation of China(Nos.51272193,51372183,51072150)Program for New Century Excellent Talents in University(No.NCET-10-0660)the National Key Research Projects(No.2016YFB0303501)
文摘Composition, morphology, and structure of hydration products in hardened pastes of three kinds of blended cement（cement-silica fume, cement-quartz powder and cement-silica fume-quartz powder） hydrated under different curing regimes（standard curing, 90 ℃ steam curing, 200 ℃ and 250 ℃ autoclave curing） were investigated by X-ray diffraction and field emission scanning electron microscope equipped with EDAX system. Results showed that the main hydration products in three kinds of hardened pastes under standard curing condition are all C-S-H gels, CH, and AFt. Under 90 ℃ steam curing condition, the main hydration products of cement-silica fume and cement-silica fume-quartz powder are C-S-H gels, whereas those of cement-quartz powder are C-S-H and CH. Under 200 or 250 ℃ autoclave curing condition, no obvious crystallized CH phase is found in hardened pastes of three kinds of blended cement, and C-S-H gels are transformed into one or more crystalline phases such as tobermorite, jennite, and xonotlite. The chemical composition and morphology of these crystalline phases depend on the composition of mixture and autoclave temperature.
