Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/86539
HighwayContractor Subgrade Stiffness The subgrade stiffness is essential for pavement design and evaluation. This paper presents the effect of various soil properties on the subgrade stiffness in the fi eld. Data was extracted from the Long Term Pavement Performance (LTPP) Seasonal Monitoring Program (SMP) database. In this study, the subgrade stiffness was charac- terized by the Base Curvature Index (BCI), and the subgrade modulus calculated through the back calculation process. Passing the #200 sieve, maximum dry density and water contents as soil properties were selected to associate with the subgrade stiffness characterization. It was found from this study that the BCI and subgrade modulus are highly correlated with soil proper- ties. It was also observed that the water content is the most signifi cant parameter determining the subgrade stiffness. Paper is entitled: Assessment of Infl uence of Soil Properties on Subgrade Stiffness Using the Long Term Pavement Performance Data Coal Ash Value The research consists in examining the applicability of two kinds of ash (fl y and bottom) of coal combustion residue from thermal power, on the layers of pavements base road by mixing these ashes with a non-lateritic sandy-silty soil, characteristic of the Rio de Janeiro state, with and without lime addiction. This study presents the results of physical and chemistry characterization, and compression, resilient modulus and permanent deformation, beyond environ- mental testing solubilization and leaching. These tests were conducted on the pure soil, on the ashes and on soil with fl y ash and bottom ash mixtures, with and without lime ad- diction. Mixtures with ash addiction initially showed a me- chanical behavior consistent with the requirements for low traffi c roads. The results show that the soil is dependent on confi ning pressure and the inclusion of fl y ash and the mix- ture cure dramatically increase the value of resilient modu- lus, on the other hand, the addiction of bottom ashes in this type of soil has increased immediately the resilient modulus of the mixtures. Paper is entitled: Applicability of Coal Ashes to Be Used for Stabilized Pavements Base And the bauma folks say an average annual growth in the global construction industry of more than 4 percent until 2015 will ensure a sustained demand for plant and machinery. B The last bauma [offi cially the International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines, Construction Vehicles and Construction Equipment] in 2010, attracted 3,256 exhibitors from 53 countries and over 420,000 visitors from more than 200 countries, numbers the Munich, Germany, show now ex- pects to see eclipsed at the April, 2013 event. The show delivers approximately six million square feet of exhibition space. All of that vastness was fully booked by May of this year, eleven months before the event. What's more show administrators say they have a waiting list for all sections of the exhibition, despite the creation Bauma: The Biggest Gets BIGGER auma, the world's largest trade show, says it is on track for a new attendance record and has a wait- ing list of exhibitors clamoring for space. of 160,000 square feet of new display area. "With this additional space we can now admit more exhibitors than at the last event," says Georg Moller, ex- hibition group director at Messe München International. "Nevertheless it is still not possible to accommodate all those who want to take part, or to meet in full the space requirements of all participants." That's not the only good news from the bauma folks. They also say the European construction and building material machinery industry remains optimistic despite growing fears about the Euro crisis. In an offi cial statement, bauma says that, "The signals for medium- to long-term growth in the construction and building material machinery industry are positive: world- wide construction activity has grown signifi cantly in recent years. Growth is being driven by the up-and-coming de- veloping and emerging countries led by the BRIC [Brazil, Russia, India, China] states." Online pre-registration begins this month. Better Roads October 2012 9