Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : aggregate


Selecting the Optimum Graphical Method to Find Aggregate Blend Proportions in the Production of HMA

Talal Hussien Fadhil

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1636-1655

The proportions of aggregate directly affect the performance of HMA depending on their shape, texture, and strongly on the gradation.The determination of aggregate proportions depends strongly on the number of aggregate typesto be blended, and the limits of the desired gradation.
In this research, ten samples had been taken from different text books and papers. Each one contains three types of aggregates; coarse, fine, and filler. The samples were solved individually by seven different methods; five of them by graphical method, the sixth method was solved by running MATLAB, and the last method by using Excel sheet. In this research, five graphical methods were applied, and the aim of using them is to find graphically the tentative blending values and then compare their results individually with optimum values which was found from an Excel spreadsheet, and finally selecting the optimum method. For this purpose, more than 210 readings were utilized.
SPSS program was run two times. In the first run, the values of person correlation (r) of method,Balanced-Areas (Rothfuchs), Walace, Equal Distance, Triangular, and Asphalt Institute when correlated with optimum values were 0.973, 0.964, 0.958, 0.953, and 0.869, respectively. In the second SPSS run, the values of samples No.4 and No.10 were removed because they gave zeros readings, the person correlation of Triangular, Balanced-Area, Walace, Equal Distance, and Asphalt Institute methods were 0.972, 0.970, 0.959, 0.952, and 0.869, respectively.
In this research, It has been found that the Equal Distances method would be considered as an accurate, fast, and even easy method, and can be used for any number of aggregate.

Improvement of Soil by Waste Tires Addition

Falak O.Abas; Mohammed .O.Abass; Raghad.O.Abass; Shymaa K.G

Engineering and Technology Journal, 2011, Volume 29, Issue 16, Pages 3417-3428

Low able fill material is a self – leveling– compacting one; these types of material rapidly gain acceptance and application in construction utility earthworks. The use of scrap tires as a reinforcement element is an attractive solution that combines the
advantage of improving soil mechanical behavior with environmental concerns. The present work describes an experimental study on replacing sand aggregate grain size with wastes rubber and plastics at different mixing ratio (6, 18, 30) % wt. respectively to support technical feasibility of muddy soil by using wastes materials then compared with commercial additives (carbon fiber) afterward check their hydrodynamical
properties (E.L, P.L, hydrometer, compaction, and sp.gr) of prepared
compacting improved soil mixtures. Experimental results indicate that crumb rubber have successfully used to produce a light weight flow able fill ( 1.2 to 1.6 g/ cm3 ) than other additive waste plastic and carbon fiber based on the characteristic properties (E.L, P.L, hydrometer, compaction ) as follows:
Have 65% for rubber samples than other additives of 45% and 55% molecules respectively for hydrometer test, 2 Gs for rubber than 1Gs for other additives; and 560 g/cm3 compaction for rubber additive than 520 g/cm3 for other additives carbon fiber and waste plastic.