Advanced Materials Research Vol. 911

Abstract: Enhancing the quality of AC 60/70 using crumb rubber and SBS polymer has its limitations. These limitations are in terms of lower than standard penetration properties, softening point and ductility based on the polymer modified asphalt cement TISI 2156-2547 standard. This research aimed at eliminating the problem by using AC 80/100 and modifying it with crumb rubber or SBS polymer at different quantities. Two types of AC were compared in this research. The qualities tested were penetration, softening point, ductility, flash point and weight loss due to heat. The results of the quality of properties tested were analyzed based on TISI 2156-2547 standardfor AC. Furthermore, the research goes on to analyze the cost effectiveness of the modification and found that modified AC 80/100 has better qualities than AC 60/70 but is 5% higher in cost. Modifying AC 80/100 with 5 wt.% crumb rubber and 4 wt.% SBS polymer will decrease the penetration and ductility problem compared to modifying AC 60/70 with the same additives. However, the softening point is still a problem for both grades of AC.

Abstract: Foam concrete is a lightweight concrete which is produced relatively inexpensively. However, due to its low strength and brittleness the application in building construction is rather limited. A study has been undertaken to investigate the effects of polyolefin fibers at a relatively low volume fraction (0 %, 0.2 %, 0.4 % and 0.6 %) on the compressive and flexural properties of foamed concrete. The foamed concrete was designed to achieve a target strength of 8-10 MPa with a density of 1600 kg/m³ at the age of 28 days. For each mixture, nine 100x100x100 mm cubes and three 100x100x500 mm beam were prepared. The compressive test was performed on cubes and three points loading flexural test on the beams was carried out in accordance to MS 26:Part 2:1991. Test results showed that polyolefin fibers only slightly improved the compressive strength and flexural strength of foamed concrete by 4.3% and 9.3% respectively.

Abstract: Sulfate attack and its effects are important from both scientific and industrial viewpoints. Itis perceived that cements containing pozzolan have better performance in sulfate solutions,since the pozzolanic reactions reduce the quantity of calcium hydroxide and increasecalcium silicate hydrate. This paper investigates the physical and mechanical properties ofconcretes made by blended cement containing Algerian natural pozzolan of volcanic origin, and Portland cement. in order to better determine the pozzolanic effect of the pozzolan addition in the concrete, the analysis of the experimental results of the effect of the partial replacement of the cement by the naturalpozzolana showed that it contributes positively to the improvement of its mechanical characteristics, its durability with respect to the permeability to the chlorine ions, the ultrasonic pulse velocity as well as the sulphate resistance. The present study confirms the pozzolanic reactivity of the natural pozzolans used.

Abstract: A new method of stability evaluation of the stage-constructed embankment on soft ground using stress path is developed and presented in this paper. A series of CU tests was carried out to develop the new method to evaluate the stability of soft ground. A new concept of stability index (SI) is defined with stress path. The effective stress path (ESP) line approaches to the K_f line gradually along the same direction to a certain point, then the direction changes and approaches to the K_f line rapidly. The potential of failure increases swiftly when SI is less than 0.4, and the value of SI=0.4 could be assumed as a representative value to evaluate the potential of failure for the tested material.

Abstract: In the empirical case studies of the seven detached house buildings situated in Yilan, Taiwan in a hot and humid climate, this research conducted the actual measurements and analysis of the Summertime Indoor and Outdoor thermal environment parameters in order to accomplish the research of Time Lag Phenomenon of Summertime Indoor Temperature and Humidity in the Buildings of Light (Composite) Constructions and Heavy (Reinforced Concrete) Constructions. Firstly, it indicated that given the condition of doors and windows in closed positions, there would be Time Lag Phenomenon for both of the indoor Temperature and Humidity measurements in domestic buildings. The Temperature Time Lag for Heavy Construction Buildings had a duration of around three hours, almost as twice that of the figure for Light Construction Buildings. There was a significant correlation between Quantity of Interior Finishes and Humidity Time Lag inside domestic buildings, whereas the bigger the Quantity of Interior Finishes, the longer the Humidity Time Lag. Secondly, it also showed that given the condition of doors and windows in opened positions, there was almost zero Time Lag for both of the domestic indoor Temperature and Humidity measurements. Last but not least, generally speaking, the Ratio of Indoor/Outdoor Diurnal Temperature Range of Light Construction Buildings were higher than that of Heavy Construction Buildings. In particular, given the condition of doors and windows in opened positions with natural ventilation in summertime, it was slightly cooler inside the Light Construction Domestic Buildings than the Heavy Construction Domestic Buildings.