M E C H A N I C A L A N D P H Y S I C A L P R O P E R T I E S O F E X P A N D E D P O L Y S T Y R E N E S T R U C T U R A L C O N C R E T E S C O N T A I N I N G M I C R O-S I L I C A A N D N A N O-S I L I C A
Author(s):
Article Type:
Research Note (دارای رتبه معتبر)
Abstract:
In this paper, the mechanical and physical properties, such as strength, water absorption, type of curing, failure mode and microstructure of expanded polystyrene (EPS) structural lightweight concretes modified by Micro-silica and Nano-silica, were investigated. In the specimens without EPS beads, replacement of Micro-silica and Nano-silica up to 15% and 3% wt of cement, respectively, led to the increase of compressive strength and decrease of water absorption; after that, these trends were vice versa. These amounts of the concretes containing EPS were 10% and 2%, respectively. By replacing nearly each 5% of Micro-silica or each 1% of Nano-silica, the compressive strength increased by approximately 10% to 15% and water absorption decreased by approximately 15% to 20%. These results showed that the effect of 1% Nano-silica is almost equal to the effect of 5% Micro-silica, though it is more costly. In concretes containing EPS without silica materials, EPS beads do not have sufficient adhesion with the cement paste, and the transition zone between EPS and cement paste has a relatively large width. Therefore, by adding Micro-silica and Nano-silica to the concretes containing EPS beads, proper adhesion between the EPS beads and other concrete components was formed as confirmed by the SEM images of the specimens. On the other hand, the use of EPS beads in the concrete mixture led to increasing the slump and workability of the concretes and significant reduction in their compressive strength, density, and water absorption. Therefore, the result indicated that the use of EPS beads in concrete changed the concrete's failure mode from diagonal lines, brittle mode to soft, and parallel lines mode. In addition, the effects of three curing methods with water, limewater and water steam on the strength and water absorption of concretes were investigated. The findings showed that 28-day limewater and 1-day water steam curing resulted in the highest strength and the lowest water absorption compared to other curing methods.
Keywords:
Language:
Persian
Published:
Sharif Journal Civil Engineering, Volume:34 Issue: 1, 2018
Pages:
123 to 132
magiran.com/p1853499
دانلود و مطالعه متن این مقاله با یکی از روشهای زیر امکان پذیر است:
اشتراک شخصی
با عضویت و پرداخت آنلاین حق اشتراک یکساله به مبلغ 1,390,000ريال میتوانید 70 عنوان مطلب دانلود کنید!
اشتراک سازمانی
به کتابخانه دانشگاه یا محل کار خود پیشنهاد کنید تا اشتراک سازمانی این پایگاه را برای دسترسی نامحدود همه کاربران به متن مطالب تهیه نمایند!
توجه!
- حق عضویت دریافتی صرف حمایت از نشریات عضو و نگهداری، تکمیل و توسعه مگیران میشود.
- پرداخت حق اشتراک و دانلود مقالات اجازه بازنشر آن در سایر رسانههای چاپی و دیجیتال را به کاربر نمیدهد.
In order to view content subscription is required
Personal subscription
Subscribe magiran.com for 70 € euros via PayPal and download 70 articles during a year.
Organization subscription
Please contact us to subscribe your university or library for unlimited access!