Discussion: View Thread

Expand all | Collapse all

Rehabililtaion of Concrete Structure

  • 1.  Rehabililtaion of Concrete Structure

    Posted 09-25-2017 11:05 AM
    We are planning for the project on rehabilitation of concrete structure subjected to corrosion using bamboo. We are actually naive for the project on a concrete structure. Bamboo has been used as a substitute for steel reinforcement and enough research has not been made on this issue. Does anybody have <g class="gr_ gr_206 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar only-ins doubleReplace replaceWithoutSep" id="206" data-gr-id="206">idea</g> on this matter? It would be very helpful to move forward if we could get hands-on research paper based on this.

    Ashish Ganesh S.M.ASCE

  • 2.  RE: Rehabililtaion of Concrete Structure

    Posted 09-26-2017 09:41 AM
    Refer attached file. It might help you.

    Ravi Bhatt S.M.ASCE

  • 3.  RE: Rehabililtaion of Concrete Structure

    Posted 09-26-2017 09:43 AM
    Back in the 1970's Lehigh University did a surprising amount of research on bamboo reinforced concrete,  Concrete repairs may require that only a small percentage of the existing embedded steel has deteriorated to the point that it needs to be reinforced.

    David Heckman P.E., M.ASCE
    Restoration Pro
    Media PA

  • 4.  RE: Rehabililtaion of Concrete Structure

    Posted 09-26-2017 09:43 AM
    You are right that bamboo has been used to reinforce concrete but I believe that there are a number of reasons to find another approach.

    First you have the question of establishing design values.  What do you know about the variability of the properties of bamboo?

    I doubt that bamboo has the ductility that modern concrete codes assume.

    Mark Gilligan P.E., M.ASCE
    Berkeley CA

  • 5.  RE: Rehabililtaion of Concrete Structure

    Posted 09-26-2017 09:43 AM

    Organic building materials have been used for construction in the old times and have proved to be an apt choice. Bamboo has been used as the skeleton of the structure for a long time, later replaced by steel re-bars . They are still used in some rural parts in India and Africa for making small mud-huts. Given their remarkable strength when dried, bamboo stems can be used as reinforcement in small buildings.

    The problem arises with the seismic zone of the construction site. No doubt steel has much more plasticity than bamboo and thus can bear seismic forces  without leaving any impact on the building. Also, since bamboo is organic, it does not have a long life in comparison to steel reinforcement. This gets worse in areas near water bodies, especially seas and oceans which have highly corrosive water and salts that can corrode bamboo in very less time.

  • 6.  RE: Rehabililtaion of Concrete Structure

    Posted 09-26-2017 09:44 AM
    I suggest you conduct a bond strength test for bamboo in concrete

    Peerzada Basit A.M.ASCE
    Chennai TN

  • 7.  RE: Rehabililtaion of Concrete Structure

    Posted 09-26-2017 09:44 AM
    You refer to corrosion. This would normally be used in reference to steel reinforcement. Can you be more specific as to what the symptoms are for the deterioration? Are you referring to rot of the bamboo? Deterioration of the concrete matrix? Cracking? Other? If you can also supply images that would be very helpful.

    James Cohen P.E., M.ASCE
    Senior Vice President
    Newark, NJ

  • 8.  RE: Rehabililtaion of Concrete Structure

    Posted 09-27-2017 10:22 AM
    Rehabilitation of concrete structure with bamboo reinforcement is a good idea. It depends upon the availability of bamboo as well as satisfaction of required strenght, durability and ductility. Lot of research on bamboo reinforcement in the concrete  have already been done in past. Still there is a requirement of research specially in the area of composite action of bamboo in strength and ductility. The composite action can be enhanced with the help of modified concrete. 

    Rajesh Kumar A.M.ASCE
    Indian Institute of Tech.(Bhu)

  • 9.  RE: Rehabililtaion of Concrete Structure

    Posted 09-27-2017 10:26 AM
    In this aspect, the tensile strength of the bamboo must be compared with the tensile strength of steel, second thing is its ductility as steel has a well defined plastic zone to ensure the ductility of the reinforced concrete and third thing is the bond strength of bamboo must be compared with that of steel by performing the pull out tests. Steel has concrete key interlock between the ribs to initiate the splitting bond failure mechanism, which in my opinion is absent incase of bamboo.

    Kafeel Ahmed Aff.M.ASCE
    Professor of Civil Engineering
    Qassim University, Qassim Engineering College Buraydah Saudi Arabia/University of Central Punjab Lahore Pakistan


  • 10.  RE: Rehabililtaion of Concrete Structure

    Posted 09-27-2017 06:10 PM
    While working for a petroleum company in West Africa in the 1970's, US Peace Corps volunteer friends (liberal arts educated couple) assigned to a community development project in a neighboring country and I began a 15-20 day round trip snail mail correspondence on various issues generally associated with my engineering gig. After a few months, I took off a couple of weeks to visit them.

    Shortly before they arrived on their station, for some reason, the Soviet embassy had delivered to the community several hundred sacks of what appeared to be Portland cement, most of which were still carefully stacked and dry in a warehouse when I arrived. Much of the correspondence with my PC friends had been related to this ten tonne or so cache of cement and the fact that other than miscellaneous scraps of metal, there was nothing available as a reinforcement material except the planar pattern branches of a local hardwood tree commonly used for small structural slabs of  no more than 3 meters of span extent, some of which were decades old and still in service without a problem.

    The branches generally were dried for 1.5 to 2 years after cutting and of about 1+ meter sort of square in a trimmed planar aspect ratio of  an average of no more than 100 mm thickness; ''thrashing'' with poles of the dry branches broke off weak branchlettes and twigs, as well as removed bark. Slab forming consisted of a crisscrossed pattern of rough wooden planks covered with about 3 layers of trimmed palm fronds. Cement and river aggregate blended to minimum workability and form leakage, was placed in a 20-30 mm layer across the extent of the palm fronds, and the reinforcement branches was shoved down much as is occasionally done with wire mesh reinforcement. Additional layers of paste were applied until 30-40 mm below the finished top of slab surface, at which point, a 3-4 day set was allowed, following which the ''trimmers'' clipped any ''twigs'' that were higher than the planed finished slab surface.

    A couple of months before my arrival, I asked my friends to measure the weight of about a 1-2 kg sample of dried branch fragments, then submerge the sample in water for 6 weeks, shake it dry, but still visibly wet, then weigh it again of their postage scale. The ''saturated'' increase in weight was 3 per cent, not bad for an ersatz rebar. When I arrived, we broke up a couple of 15-20 year old abandoned slabs and extracted wood fragments. The concrete bond to the wood was about the same as that to smooth steel wire or rod. Several rather straight pieces between secondary branching points were hewn to a nominally square cross section, then placed as beamlettes with suspended mid-span loads. Outer fiber strength was calculated at about 35 MPa, with elastic modulus of about 150 MPa at a rather sudden rupture with very little indication of ductility, but preceded by some very audible cracking sounds.

    We did a couple of  ''test'' slabs (as squat latrine covers where a detail around the holes was identified). The branch density typically used historically in the community produced a working ''d'' from finished slab of about 0.65 slab thickness and a branch volume of 15-20 percent of total slab thickness. Aged concrete strength was not determined, but for an assumed effective 28-day compressive strength (some portion of branches included at the top of slab) of about 12 MPa, the historically typical 150 +/- mm thick 3 meter slab was rather balanced in rupture tension and compression in a one way slab analysis for a service load of 100 kg/sm. I worked out a semi-two way slab table of 6 square spans of 3 to 6 meters for the minimum slab thickness of two ranges (150 and 250 kg/sm)  of loading and multiples of branch reinforcement quantities for each based on a factor of safety (1.5) of what was customarily used for the 3 meter slabs. Other than the PC volunteers, there were 4 local persons (2 young constructors in their 20's, a nurse and the nominal public works director) who understood the process and my table.

    When I left, I put my slide rule away and thought I was finished, but the letters started flowing, several per week. What about holes? (I had a 400 mm square hole detail for the outer 2/3 of the span, but...) What about point loads other than the single center span point load of 200 mm square on a pedestal that I listed? Etc. The Soviet cement was used up in less than a year after my visit; there were not reports of failure.

    Robert Bullard P.E., M.ASCE
    Ahimsa Technic Inc
    Ponce Inlet FL

  • 11.  RE: Rehabililtaion of Concrete Structure

    Posted 09-28-2017 12:53 PM
    I would like to send you the link of the graduation project of two engineers from last year. They worked in the structural design process of a two story house with a similar material. The attached file can be found online here: http://www.dspace.espol.edu.ec/retrieve/96361/D-CD70165.pdf . As it is in Spanish, I suppose that it can be translated to English very easily.

    I only know from cases at Colombia and Ecuador but we have included these materials in our codes due to its benefits (NSR in Colombia and NEC in Ecuador).

    I hope that this information can be useful for your project.

    Roberto Anton Ing., A.M.ASCE
    ∆X Int.
    MD - Construction

  • 12.  RE: Rehabililtaion of Concrete Structure

    Posted 09-29-2017 03:43 PM

    The colossal number of seismically deficient reinforced concrete structures throughout the world forced
    the researchers to work on developing rapid and effective rehabilitation techniques. The related research
    resulted in various rehabilitation methods, among which introduction of reinforced concrete (R/C) infills
    was proven to be very effective. This particular method has found wide acceptance all over the
    world and has been applied successfully.

    Here I have attached a research paper which was published on  13th World Conference on Earthquake Engineering
    Vancouver, B.C., Canada.

    Muhammadh Ishqy S.M.ASCE
    Department of Civil and Environmental Engineering
    University of Ruhuna.

  • 13.  RE: Rehabililtaion of Concrete Structure

    Posted 10-16-2017 03:28 PM


    There are some researches regarding the FRC beams and their behavior which might be helpful for you. There are also some generalized back calculations (Inverse Analysis) that can be used to estimate the stress-strain curve for the FRC samples. Here are the links to some of the papers and Excel worksheet that can be used for FRC structures. You can Also find these worksheets in ACI website.

    1-ACI Committee 318-14 ,Building code requirements for structural concrete (ACI 318-14) and commentary,American Concrete Institute. Farmington Hills,MI48831.

     2-Yao, Y., Mobasher, B.,  Soranakom, C. "Closed Form Solutions for Flexural Design of Hybrid Steel Fiber Reinforced Concrete Beam", Engineering Structures; 100:164-177 · September 2015.

     3-Soranakom, C., and Mobasher, B., "Flexural Design of Fiber Reinforced Concrete," ACI Materials Journal, September-October 2009, pp. 461-469

     4-ACI 544.6R-15 Report on Design and Construction of Steel Fiber-Reinforced Concrete Elevated Slabs, Committee Chair, ACI Committee 544 ACI 544.6R  (2015)

     5-ACI 566.7R-16 Report on Design and Construction of Fiber-Reinforced Precast Concrete Tunnel Segments ACI Committee 544 ACI 544.7R  (2016)

     6-ACI 544.8R-16: Report on Indirect Method to Obtain Stress-Strain Response of Fiber-Reinforced Concrete (FRC), ACI Committee 544 ACI 544.8R  (2016)

     7-Mobasher, B., Yao, Y., Soranakom, C., Dey,V., "A Spreadsheet-Based Inverse Analysis Procedure for Flexural Specimens – Strain Softening/Hardening Behavior, November 2015, DOI: 10.13140/RG.2.1.4409.2882  


    Farrokh Kianmofrad S.M.ASCE
    Tempe AZ

  • 14.  RE: Rehabililtaion of Concrete Structure

    Posted 10-31-2017 05:09 PM
    Edited by Thomas Halmi 11-10-2017 01:59 PM

    In 1966, the U. S. NAVAL CIVIL ENGINEERING LABAORATORY reviewed the use of bamboo for reinforcement of P.C.C.  They noted that the use of bamboo as reinforcement in portland cement concrete has been studied extensively by Clemson Agricultural College.  Also, a study of the feasibility of using bamboo as the reinforcing material in precast concrete elements was conducted at the U. S. Army Engineer Waterways Experiment Station in 1964.  Ultimate strength design procedures, modified to take into account the characteristics of the bamboo reinforcement were used to estimate the ultimate load carrying capacity of the precast concrete elements with bamboo reinforcing.  Here are some interesting links for review: http://www.romanconcrete.com/docs/bamboo1966/BambooReinforcedConcreteFeb1966.htm and  https://theconstructor.org/structural-engg/bamboo-reinforced-concrete-mix-design-construction/15054/ .

    Thomas Halmi P.E., M.ASCE
    Senior Facilities Engineer