Search
Filters
Close

51315-6097-Enhanced Soil-Cementitious Fill Corrosion of Galvanized Steel Reinforcement in Mechanically Stabilized Earth Walls

Product Number: 51315-6097-SG
ISBN: 6097 2015 CP
Author: Enrique Paz
Publication Date: 2015
$0.00
$20.00
$20.00
Enhanced soil-cementitious fill corrosion of galvanized steel reinforcement in Mechanically Stabilized Earth WallsMechanically stabilized earth (MSE) walls contain galvanized reinforcing meshes or strips attached to reinforced concrete panels that stabilize the fill by means of friction. After some time the backfill may escape through the joints of the panels or compact due to water ingress forming voids that can compromise its structural integrity. These voids may be repaired by filling them with a cementitious mix known as Controlled Low-Strength Material (CLSM). This practice may have an adverse corrosion consequence as the reinforcement embedded in hardened CLSM passivates due to the high pH of the pore water while the portion embedded in regular soil tends to be in the active condition thus a macrocell that can aggravate corrosion on the soil side may be established.To quantify the extent of this effect for future practice improvement preliminary small scale experiments were carried out using specimens containing pairs of galvanized steel wires buried one in soil backfill and the other in CLSM. Larger scale experiments with 8ft x 4ft x 3ft boxes were also conducted to better represent the geometry and conditions inside an MSE wall. One octant of the boxes acted as a simulated void and was filled with CLSM. Electrochemical Impedance Spectroscopy was used to assess the initial condition of the reinforcements which were then electrically connected to establish a macrocell. Corrosion rates and macrocell action were measured to assess the extent of the adverse coupling. Initial results indicate that in regions that experience macrocell enhancement due to the presence of CLSM in the system corrosion activity can be about three times worse compared to a backfill-only system. Finite Element electrochemical modeling of the system supports this finding. Alternative materials with a lower pH are being evaluated to propose an alternative to CLSM. Predictive models are presented to evaluate the benefit of alternative void filling strategies and aid in decision making for repairs.
Enhanced soil-cementitious fill corrosion of galvanized steel reinforcement in Mechanically Stabilized Earth WallsMechanically stabilized earth (MSE) walls contain galvanized reinforcing meshes or strips attached to reinforced concrete panels that stabilize the fill by means of friction. After some time the backfill may escape through the joints of the panels or compact due to water ingress forming voids that can compromise its structural integrity. These voids may be repaired by filling them with a cementitious mix known as Controlled Low-Strength Material (CLSM). This practice may have an adverse corrosion consequence as the reinforcement embedded in hardened CLSM passivates due to the high pH of the pore water while the portion embedded in regular soil tends to be in the active condition thus a macrocell that can aggravate corrosion on the soil side may be established.To quantify the extent of this effect for future practice improvement preliminary small scale experiments were carried out using specimens containing pairs of galvanized steel wires buried one in soil backfill and the other in CLSM. Larger scale experiments with 8ft x 4ft x 3ft boxes were also conducted to better represent the geometry and conditions inside an MSE wall. One octant of the boxes acted as a simulated void and was filled with CLSM. Electrochemical Impedance Spectroscopy was used to assess the initial condition of the reinforcements which were then electrically connected to establish a macrocell. Corrosion rates and macrocell action were measured to assess the extent of the adverse coupling. Initial results indicate that in regions that experience macrocell enhancement due to the presence of CLSM in the system corrosion activity can be about three times worse compared to a backfill-only system. Finite Element electrochemical modeling of the system supports this finding. Alternative materials with a lower pH are being evaluated to propose an alternative to CLSM. Predictive models are presented to evaluate the benefit of alternative void filling strategies and aid in decision making for repairs.
Also Purchased
Picture for Dilute Flowable Backfill for Corrosion Mitigation of Buried Steel Pipe: Experimental Procedure
Available for download

51312-01750-Dilute Flowable Backfill for Corrosion Mitigation of Buried Steel Pipe: Experimental Procedure

Product Number: 51312-01750-SG
ISBN: 01750 2012 CP
Author: Scott Lux
Publication Date: 2012
$20.00
Picture for 01638 APPLICATIONS OF GALVANIZED REBAR
Available for download

01638 APPLICATIONS OF GALVANIZED REBAR IN REINFORCED CONCRETE STRUCTURES

Product Number: 51300-01638-SG
ISBN: 01638 2001 CP
Author: S.R. Yeomans
$20.00