Short Memo: Aspects & Impacts of Porous Pavements The purpose of this short memo is to discuss aspects of use, applicability, and environmental impacts of porous pavements as gleaned from practical findings and pertinent examples. A porous pavement is one with high enough porosity and permeability to allow rain and snowmelt to pass through it, thereby reducing the runoff from a site and surrounding areas. In intensely built up areas, pavements account for more than half of all the land, and for about two-thirds of total built cover (Ferguson, 2005, 2-3). Parking lots, in particular, account for the majority of paved areas. Pervious paving materials have the capability of providing a dual purpose in parking and other areas with low to moderate traffic; they serve both as a parking/traffic area and to manage stormwater. Components & Function There are several types of porous pavements, namely porous asphalt, porous concrete, and numerous modular paver systems. Both a construction material and a design technique, systems may be used individually or enhanced through a combination of types. Porous asphalt consists of an open-graded coarse aggregate bonded together by asphalt cement. The mixture contains fewer fines than traditional asphalt and sufficient void space between aggregate particles allows water to drain through quickly. Porous concrete also consists of an open-graded coarse aggregate, formulated with Portland cement and water. Modular porous pavers are structural units, such as concrete blocks or reinforced plastic mats, with void areas that are filled with pervious materials, to achieve a load-bearing permeable surface. The pervious fill materials include sand, grass turf, and gravel. Each of these surfaces is typical... ... middle of paper ... ...rent purposes. Residential streets and interstate shoulders have been constructed of porous systems, and more extensive weight-bearing roads are functioning in Europe. More research and site study of porous paving techniques and specifications are needed to continue to increase knowledge and implementation of these systems, and to further their capacity for use. Works Cited Adams, Michele (May/June 2003). “Porous Asphalt Pavement With Recharge Beds,” Stormwater Magazine. www.forester.net/sw_0305_porous.html Ferguson, Bruce (2005). Porous Pavements. FL: CRC Press. Georgia Stormwater Management Manual (2001). “Porous Concrete.” Vol. 2, 3.3-33 - 3.3-40. Georgia Stormwater Management Manual (2001). “Modular Porous Paver Systems.” Vol. 2, 3.3-41 – 3.3-46. U.S. EPA (September 1999). Stormwater Technology Factsheet: Porous Pavement. Washington, DC: EPA 832-F-99-023.
When construction takes place, it is usually way before it is actually needed. Of course it is helping prevent dangerous and fatal occurrences but for the most part some of these changes can wait. Instead of spending so much money on our transportation category we should be putting more into education. “The money that the Federal Budget gives for education covers college aid loans, special education programs, free lunch to students in need, anti-discrimination efforts, research, and special programs” (Document D). Education is one of the most important things a person can have. ”
...believe that the state should consider putting more money into repairing roads, both gravel and highway, so they are useable. Many of the people who do not live in town and use the gravel roads everyday could benefit tremendously from this.
Griffith, A. (1998). Improved winter pothole patching. Salem, OR: Oregon Dept. of Transportation, Research Unit.
Stone Mastic Asphalt (SMA) has a course aggregate skeleton like porous asphalt but the voids are filled with a fine aggregate/filler/bitumen mortar. It differs from hot rolled asphalt (HRA) in that the mortar is designed to just fill the voids in the course aggregate, whereas in hot rolled asphalt, course aggregate is introduced into the mortar and does not provide a continuous stone matrix.
Introduction: Rainwater runoff, also called non-point source, is everywhere, especially in the artificial concrete communities that we live in. Rainwater runoff occurs after rain showers and thunderstorms, when the water flows down streets, sidewalks and gutters. There is so much rainwater runoff now a day because of the colossal neighborhoods and buildings and parking lots we are creating. The runoff happens when the water can’t soak into the ground, like it naturally does. With growing cities and industrialization, runoff water is becoming more and more of a problem and people need to start worrying about it. Runoff water has the possibility of becoming very dangerous, depending on what the water takes with it. Pesticides, garbage, bacteria, sediments from roads, feces and oil/gasoline are just some of the many substances that rainwater runoff carries with it on it’s journey; and lets not forget about all of the possible toxic chemicals that would fall into its path. So many residencies have been built, causing more runoff water because it isn’t being absorbed into the soil, since the soil is covered in concrete or other substances that were used to build. Everything that rests in gutters also goes down into the soil and in sewers that dump water into soil or other bodies of water, and the effects can both be positive and negative. Substances such as phosphate can travel with the runoff water into areas with soil and grass, causing it to grow faster. While some people may think fast growing grass is helpful, lets not forget about the rest of the environment the phosphate can effect. Certain algae’s can be harmful to humans when ingested. After knowing that, people should realize that it is time for environmental management to co...
This reports presents the process of answering the following question, is sodium chloride a viable option for reducing ice on Minnesota roads? The answer to this question relies heavily on how well sodium chloride decreases the freezing point when dissolved in water, as well cost and its environmental impact. To determine this, the freezing point of varying molality’s of sodium chloride were compared to pure deionized water. The results of this experiment revealed that as more sodium chloride was dissolved, the freezing point depression increased. These values were anywhere from -1.14 and -4.51 degrees Celsius. Another strong indicator of sodium chlorides ability to deice roads is its enthalpy of dissolution. An exothermic reaction is preferred
NCHRP 2004a Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures, National Cooperative Highway Research Program, NCHRP, Part 2– Design Inputs, Chapter 2 Material Characterization”.
In this report, we will introduce and illustrate on precast concrete, pre-stressed concrete, ready-mix concrete, reinforced concrete, terrazzo and Urbanite in details.
Bored piles construction is done using the suitable rotary drills depending on the diameter, depth, condition of the soil and construction method. Usually bore-holes are stabilized with a temporary or permanent casing. The common material used for the casing is steel and it is also normal called as steel casing. The length of the steel casing is also determined from the soil conditions that are discovered at the actual site.
One of the biggest drawbacks has to do with paved surfaces contributing to flooding and standing water contamination. Recently though, new developments in the study of this issue has led to the creation and implementation of porous (or pervious) concrete. Porous concrete is made out of the same material as regular concrete, but is structured differently. The Ready Mixed Concrete (RMC) Research & Education Foundation defines porous concrete as, “a concrete with a high percentage of interconnected voids that, when functioning correctly, permit the rapid percolation of water through the concrete.” They continue to say, “Unlike conventional concrete, which has a void ratio anywhere from 3-5%, pervious concrete can have void ratios from 15-40% depending on its application” (RMC Research & Education Foundation, 2015). RMC was founded in 1991 for the purpose of starting education programs about concrete. Their definition highlights the fact that porous concrete will allow large amounts of water to flow through it, greatly reducing the accumulation of water on the surface of the pavement. This is possible because the top layer of the material is made up of small, connected rocks that leave reasonable amounts of empty space between them for water to flow down, as opposed to regular concrete which has 10-37%
Benefits of utilizing an EPS-block geofoam embankment include: (1) ease and speed of construction, (2) placement in adverse weather conditions, (3) possible elimination of the need for preloading, surcharging, and staged construction, (4) decreased maintenance costs as a result of less settlement from the low density of EPS-block geofoam, (6) reduction of lateral stress on bridge approach abutments, (7) use over existing utilities which reduces or eliminates utility relocation, (8) excellent durability, and (9) ability to be recycled. In a soil removal and replacement situation without the use of surcharging, the use of EPS-block geofoam may result in cost savings compared to other types of lightweight fill materials and conventional fill materials because the density of geofoam is 1/10th to 1/30th of the density of foamed concrete, 1/55th to 1/145th of the in-place density of boiler slag, and 1/100th of the density of conventional granular fill
Safdie, M 1966, Habitat, a design for high-density urban living, Cement and Concrete Association, London.
Restoring and Improving Urban Infrastructure - Engineering Challenges. " EngineeringChallenges.org -. National Academy of Science, 2012. Web. The Web.
Gravel reminds me of city streets, lit up twenty-four hours a day and providing plenty of reason to hustle through the daily traffic jam. Specifically, I remember clearly how eons would pass by in cars, buses, or trains waiting to get home as the city became larger and longer. Strips of