Landscape Contractor / Design Build Maintain

NOV 2017

LC/DBM provides landscape contractors with Educational, Imaginative and Practical information about their business, their employees, their machines and their projects.

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34 LC DBM The Continuing Quest for Greener Concrete Researchers Fear Monarch Butterfly Extinction Undergraduate Enrollment Decreases, Except in Construction Fields Researchers at Princeton University are continuing to evaluate techniques to improve results using con - crete made with alkali-activated materials, a Portland cement alternative whose production creates up to 90 percent less carbon emissions, and has been shown to be as strong as the traditional material but does not have proven long-term durability. Their findings so far have offered hope in reducing age-related cracking of concrete made with these greener materials and lowering its permeability. Estimates from the Xerces Society's Western Monarch Thanksgiving Count put the western monarch butterfly's overwintering population in California at about 10 million in the 1980s and 1990s. The population is now estimated to be roughly 300,000, as monarchs have seen a population decline of about seven percent per year. Researchers estimate that there is a 72 percent likelihood that western monarchs will become extinct within 20 years if conditions do not change in the butterfly's favor. A report from the National Stu- dent Clearinghouse Research Center indicated that undergraduate enroll - ment fell by 1.9 percent, or 272,000 students, between the spring semester 2016 and the spring semester 2017. In contrast, the number of undergrad - uates enrolled in construction trades – including carpentry, management and more – increased by 26.4 percent. Coffee for Your Lawn? Researchers from Texas A&M University are look - ing at the effectiveness of using spent coffee grounds as fertilizer. Ten different treatments, including composted coffee grounds, fresh coffee grounds, organic fertilizers, and synthetic fertilizers, are being compared on different plots of turf. After two years, the turf will be evaluated on growth, quality and color. MIT Students Strengthen Concrete with Plastic and Radiation A group of undergraduate students from MIT found that mixing particles of plastic that have been exposed to gamma radiation with Portland cement can make concrete up to 20 percent stronger than traditional concrete. Gamma radiation is harmless, but creates a stronger crystalline structure in the plastic that then makes the concrete stronger overall. The students are continuing their study by experimenting with dif - ferent types of plastic and different levels of gamma radiation.

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