Geotechnical Lightweight Fill Competition

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Mildred Jennings
6 years ago
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1 Getechnical Lightweight Fill Cmpetitin Overview Lightweight getechnical fill has been used in place f sil fr building radway embankments, retaining walls, and as backfill abve buried pipelines as a mre ecnmically viable and lightweight material. Expanded plystyrene, als called gefam, is typically used in these applicatins. Apart frm many advantages, using gefam has drawbacks including: adverse envirnmental impact, incmpatibility with petrleum prducts, flammability, etc. Research regarding recycled lightweight fill has been cnducted t investigate the pprtunity t replace gefam with a mre sustainable and ecnmically viable material. Diverting ptentially recyclable material frm landfills and repurpsing it fr use in civil engineering applicatins ffers many envirnmental benefits, as well as saving manufacturing and prcessing csts. Fr example, ne prject used PET bttles as subgrade fr bike trails, but the prf f cncept has nt yet been expanded t radway prjects (Graettinger, 2005). Objective The bjective f the Getechnical Lightweight Fill Cmpetitin is t create a new sustainable lightweight fill and explre the mechanical prperties, sustainability, and cnstructability f this new material as a lightweight getechnical fill. The participants will create a new recycled lightweight fill material, characterize the material, and test the material strength thrugh an uncnfined cmpressin test. Eligibility Each team may cnsist f a maximum f fur (4) members, ne (1) f which may be a graduate student. Materials Materials required fr this cmpetitin are: Calculatr Pen/Pencil Recycled material used in lightweight fill Binding agent

2 Executin Cnstructin Guidelines Each team will cnstruct ne 2 ft. x 2 ft. x 2 ft. cube frm recycled material prir t the cmpetitin. Teams must use easily accessible recyclable material that can be held tgether with a binding agent. Each material used must be listed n the material breakdwn frm and justified as sustainable, recyclable, and cnstructible n the material prperties frm. There cannt be any liquid in the lightweight fill cubes. Figure 1 (a) shws an example f lightweight fill cubes that were cnstructed frm empty plastic bttles using varius binding agents. Testing Prcedure Each team will bring its lightweight fill cube t the designated testing area at the cmpetitin. Befre testing, each cube f lightweight fill will have t fit cmpletely inside a 2 ft. x 2 ft. x 2 ft. mld in all rientatins. Cubes that cannt fit thrugh the mld will be disqualified. Nte: All team members must be wearing lng pants and clsed ted shes t be admitted int the testing lab. 1. Ttal weight f the cube: Each team will recrd a weight fr the lightweight fill cube n the material prperties frm. Ttal weight may nt exceed 100 punds. 2. Uncnfined cmpressin test: The cubes will be subjected t an uncnfined cmpressin test. Due t time cnstraints, cubes will be tested t a maximum strain f 15% and a maximum cmpressive lad f 16,000 punds. The cubes will be cmpressed at a lading rate f 3% strain per minute. Cubes must meet a minimum lad f 1,000 punds at 15% strain. 3. Calculate weight/lad rati: Based n the lad and displacement values generated thrughut the cmpressin test, students will receive a stress vs. strain curve, a maximum uncnfined cmpressive lad value, and a Yung s mdulus value generated frm the test. The peak stress (max 4,000 lb/ft2) and peak strain (max 15%) values will be used t calculate the weight/lad rati. The maximum uncnfined cmpressive strength, Yung s mdulus, and weight/lad rati will be recrded n the material prperties frm. 4. Justificatin: Students will justify the sustainability and cnstructability f the lightweight cube by writing a justificatin statement n the material prperties frm. Teams shuld cnsider cst per cubic ft, secnd-use applicatins, reginal availability, renewability, durability, and address any barriers that wuld prevent the widespread use f the material as a lightweight fill. The statement may be handwritten in the space prvided n the material prperties frm r typed prir t the cmpetitin and brught t the testing

Once each team submits its cube, they will nt be able t make changes t it. (a) (b) Figure 1.

3 lcatin. The typed statement shuld be single-spaced, 12 pint fnt, and a maximum f ne (1) page lng. The University f Alabama will supply the testing apparatus, shwn in Figure 1 (b), as well as technicians wh will run the test. Once each team submits its cube, they will nt be able t make changes t it. (a) (b) Figure 1. (a) Example lightweight fill cubes (b) Cubes will be tested by vertically lading the tp and bttm f the sample using a MTS Alliance RF/150 testing machine. Requirements The cnstructin and testing requirements are summarized belw. Cube must fit inside a 2 ft. x 2 ft. x 2 ft. mld in all directins prir t cmpetitin. Cube must be made primarily f recycled material. (It is at the judges discretin what cnstitutes a recycled material, majrity rules) Weight may nt exceed 100 punds. Cube may nt include any liquid.

4 Teams must take their cube with them after it has been scred. Cubes may nt be dispsed f n campus r left in the testing lab after the cnclusin f the cmpetitin. Items submitted t the judges during the cmpetitin: 2 ft. x 2 ft. x 2 ft. lightweight fill cube Material prperties frm Justificatin write-up (if nt handwritten n the material prperties frm) Material breakdwn frm Material Breakdwn Frm The material breakdwn frm shuld be cmpleted prir t the cmpetitin and submitted alng with the ther items t the judges during the cmpetitin. Each material and binding agent used in cnstructing the cube shuld be listed in the Material clumn. Fr each material, calculate the percent f the ttal vlume and the percent f the ttal weight that the material represents in the sample. Estimate the unit cst per cubic ft f lightweight fill and the sub-ttal fr each material. A price fr any dnated r free materials shuld be included in the cst. Sum the sub-ttal values t calculate a ttal cst fr the lightweight fill sample. Specify a grain size range in the space prvided. Fr example, if PET bttles are used, the range may be frm 12 unce bttles t galln jugs. Using the ttal cst f the lightweight fill sample, estimate the cst t cnstruct a radway embankment requiring 100,000 cubic yards f lightweight fill. Judging There will be a minimum f three (3) judges fr the cmpetitin. It will be the judges duty and respnsibility t evaluate the teams fairly and cnsistently. The teams will be evaluated based n the criteria utlined in the Scring sectin included belw. The judges ruling will be final fr all cmpetitrs. Scring Teams will be scred based n the unit weight, strength, cnstructability, and ecnmy f their lightweight cube. Any type f recycled material can be used in the cmpetitin, but the team with the mst creative material will be awarded a bnus f five (5) pints. Please reference the Scring Summary Sheet fr a specific breakdwn f pints.

5 Disqualificatins Any team that des nt abide by the regulatins presented abve r perfrms unethically will be disqualified. References Graettinger, Andrew J., et al. "Recycling f plastic bttles fr use as a lightweight getechnical material." Management f Envirnmental Quality: An Internatinal Jurnal 16.6 (2005):

6 Material Prperties Frm ASCE Student Organizatin: Ttal Weight (lb): Unit Weight (lb/ft3): Max Uncnfined Cmpressive Lad (lb): Max Uncnfined Cmpressive Strength (lb/ft2): Yung s Mdulus (lb/in2): Weight/Lad Rati (lb/lb): Justificatin Statement: (respnses can cntinue nt the back f this sheet)

7 Material Breakdwn Frm ASCE Student Organizatin: Nte: A price fr any dnated r free materials shuld be included in the breakdwn. This infrmatin sheet shuld be cmpleted prir t the cmpetitin. Material (recycled cmpnents & binding material) % Vlume % Weight Unit Cst 3 (per ft f LW fill) Sub Ttal (fr 8ft3 f LW fill) TOTAL What is the grain size range f the sample? Use the cst infrmatin fr ne lightweight fill cube t estimate what it wuld cst t cnstruct a radway embankment that requires 100,000 cubic yards f lightweight fill. $

8 Scring Summary Sheet ASCE Student Organizatin: Material Breakdwn and Justificatin Statement 1. Ttal cst Lw cst = 15 pints Average cst = 10 pints High cst = 5 pints 2. Estimate cst fr 100,000 cubic yards 3. Justificatin statement /15 /5 /20 Cst & Cnstructability Sub-Ttal Material Prperties 1. Unit weight Scre Ultra-Lightweight (less than 3 lb/ft3) = 10 pints Lightweight ( lb/ft3) = 5 pints Greater than 10 lb/ft3 = 0 pints /40 Scre /10 2. Maximum strength lb/ft2 = 15 pints lb/ft2 = 10 pints lb/ft2 = 5 pints Less than 250 lb/ft2 = 0 pints 3. Yung s Mdulus All results will be split int quartiles and scred accrdingly: 1st Quartile (highest values): 10 pints 2nd Quartile: 7.5 pints 3rd Quartile: 5 pints 4th Quartile (lwest values): 2.5 pints 4. Weight/Lad Rati All results will be split int quartiles and scred accrdingly: 1st Quartile (lwest values): 20 pints 2nd Quartile: 15 pints 3rd Quartile: 10 pints 4th Quartile (highest values): 5 pints If cmpressive lad < 1000 lb: 0 pints /15 /10 /20

9 5. Failure Mde Cube defrmed, then regained riginal shape = 5 pints Cube defrmed, did nt regain riginal shape = 2.5 pints Catastrphic failure = 0 pints /5 7. BONUS: Mst creative material (judges chice) /5 Material Prperties Sub-Ttal Cst & Cnstructability Sub-Ttal Overall Scre /60 /40 /100

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