Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 1/28 PSI-Purdue-Clemson Team Federal Highway Administration Solicitation No. DTFH61-08-C Update on Objectives 1 – Tasks 1- 4 FHWA ASR Technical Working Group Meeting May 23, 2012 Austin, Texas T. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West Purdue University

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 2/28 Task 1: Role of lithium (and other ions) in preventing or reducing the effects of ASR Task 2: Role of Calcium ions in ASR Task 3: Role of deicers, hydroxyl and alkali ions Task 4: Role of aggregate Task 5: Role of Moisture and Crack Task 6: Monitoring Crack formation Objective Objective 1- List of Tasks

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 3/28 Objectives for Tasks 1, 2 and 4  Tasks 1 and 2 (Role of lithium and role of calcium)  Determination of changes in composition of the pore solution and the content of Ca(OH) 2 in mortars undergoing ASR  Correlation of changes in chemical composition in pore solution with mechanical expansion  Task 4 (Role of aggregates)  Examination of the role of chemical composition, structure and mineralogy of aggregates in the overall mechanism of ASR  Establishment of database of kinetic parameters for reactions involving silica minerals in concrete-like (high pH) environment  Development of the kinetic model for prediction of the extent of ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 4/28  Establishment of the database of kinetic parameters for reactions involving silica minerals  Having this data will help with  quantitative analysis of ASR and with  screening of potentially reactive aggregates  Establishment of the framework for predicting potential reactivity of certain types of aggregates based on the fundamental principles Potential deliverables for Tasks 1, 2 and 4

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 5/28 Progress update Specimens undergoing ASR -Changes in composition of pore solution (100%) -Changes in alkali concentration (100%) -Changes in the content of Ca(OH) 2 (100%) -Effects of temperatures (100%) -SEM analysis (60%) -Expansion (95%) Expected completion date: July., 2012 Silica minerals undergoing ASR -Changes in pore solutions (30%) -Changes in alkali concentration (40%) -Changes in the content of Ca(OH) 2 (40%) -Quantitative information about formation of ASR gel (40%) -Effects of temperatures (40%) Model linking mineralogy of aggregates with the extent of ASR -Establishment of kinetic parameters (40%) -Verification through the experiments (0%) Expected completion date: Dec, 2012 Need to Correlate Chemo- mechanical study Tasks1 and 2Task 4 -Mechanical properties of ASR gel using the nanoindentaion Expected completion date: Dec., 2012 Suggested additional Task

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 6/28 Progress update: Tasks 1&2 Experimental Program: Mortar specimens undergoing ASR Mortar specimens W/C [Li] /[Na+K] Initial Li + concentration in mix water (m)* Aggregate type and content(%) by volume Temp. (°C) NR0.55+0% Li0.5500Ottawa (50%)23, 38, 55 NR % Li Ottawa (50%)23, 38, 55 NR % Li Ottawa (50%)23, 38, 55 R0.55+0% Li0.5500Jobe (50%)23, 38, 55 R % Li Jobe (50%)23, 38, 55 R % Li Jobe (50%)23, 38, 55 NR: Nonreactive aggregate (Ottawa sand) * corrected for absorption of aggregate R: Reactive aggregate (Jobe sand) 100% Li : [Li]/[Na+K] = % Li : [Li]/[Na+K] = 0.26 Analysis of pore solutions from mortars (IC and AA) completed Quantification of the Ca(OH) 2 content (TGA) completed SEM investigation of ASR gels- ongoing Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 7/28 Effects of type of aggregate (NR and R) on alkali ions (Na + and K + ) Effects of Temperatures (55°C and 38°C) Concentrations normalized w.r.t the one day concentration values The reduction in alkali ion concentration in R mortars only, (due to formation of ASR gels) Decrease due to ASR Remain constant Decrease due to ASR Remain constant Na + ions K + ions Progress update: Tasks 1&2 Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 8/28 Effects of type of aggregate (NR and R) on OH - ions Effects of Temperatures (55°C and 38°C) Concentrations normalized w.r.t the one day concentration Remain constant Slightly decreasing In NR mortars, slightly decreasing concentration of OH - ions at 55°C Clearly decreasing trends in OH - concentration in R mortars (reaction with silica) OH - ions Decrease due to ASR Progress update: Tasks 1&2 Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 9/28 Effects of addition of LiNO 3 on concentrations of alkali ions in pore solution Effects of Temperatures (55°C and 38°C) Concentrations normalized w.r.t the one day concentration values Addition of LiNO 3 significantly reduces the loss of alkali ions (0%Li > 35%Li > 100%Li) Alkali ions do not combine with silica ions and remain in the solution Na + ionsK + ions Progress update: Tasks 1&2 Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 10/28 Effects of addition of LiNO 3 in mortar on OH - and Li + ions Effects of Temperatures (55°C and 38°C) Concentrations normalized w.r.t the one day concentration values OH - ionsLi + ions Remain constant or slightly decrease Decrease due to ASR No effects of addition of LiNO 3 on levels of OH - ions, implying that Li + ions do not have effect on the dissolution of silica (due to OH - ions attack on the silica surface) In reactive mortars, the concentration of Li + ions decreases continually Progress update: Tasks 1&2 Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 11/28 Use of kinetic law to explain the observed changes in alkali levels Threshold of [Na + +K + ]: 0.22 M Linear correlation was observed between ln[Na + +K ] and time. This can be interpreted as representing ASR as the first order reaction with respect to alkali ions. Slopes of the line represent the rate constants (k exp, s -1 )for each temperatures R0.55+0%Li Progress update: Tasks 1&2 Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 12/28 55°C 38°C 23°C R0.55+0%Li Constant value of k exp (at specific temperature) and the good fit for Arrhenius equation indicate that for a specific system (having given composition and aggregate type) the rate and the extent of ASR depend mainly on the sum of the concentration of alkali ions ([Na + +K + ]). Progress update: Tasks 1&2 Changes in chemical composition of pore solution undergoing ASR Use of kinetic law to explain the observed changes in alkali levels

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 13/28 55°C 38°C 23°C R0.55+0%Li This results strongly indicate that the ASR extent can be directly associated with a simple first order reaction in terms of [Na + +K + ] Progress update: Tasks 1&2 Changes in chemical composition of pore solution undergoing ASR Use of kinetic law to explain the observed changes in alkali levels

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 14/28 Correlation between expansion and the change in alkali levels Overall trends of expansion are very similar to the trend of the normalized consumption of available alkali ions [Na + +K ] In low temperatures, the expansion is delayed with respect to the observed consumption of alkali ions The results strongly indicate that extent of expansion can be correlated to the extent of alkali consumption Progress update: Tasks 1&2 Normalized consumption of [Na + +K ] were computed using the rate equation Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 15/28 Correlation between expansion and the change of Li + levels Progress update: Tasks 1&2 Note: Normalized consumption of [Li ] were computed using the rate equation similar to sodium rate equation The use of kinetic law to explain the observed change of Na + and K + ions more complicated in the presence of Li + ions (ongoing effort). Clear change in the expansion rate observed at the point of depletion of available Li + ions. These results seem to indicate that the Li + ions available in the pore solution are preferentially consumed in the ASR and thus suppress the expansion. Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 16/28 Change of Ca(OH) 2 content in mortars undergoing ASR Progress update: Tasks 1&2 The content of Ca(OH) 2 in the reactive mortars (with or without LiNO 3 ) remained more or less identical over time regardless of the temperature. Changes in chemical composition of pore solution undergoing ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 17/28 Progress update: Task 4 Silica minerals undergoing ASR (Reactor method) Role of the aggregates To advance the previous relation between ASR extent and [Na + +K + ] ions, the investigation of the rate constant (k exp ) is required since this constant is dependent on the nature of reactive aggregates. One of the main factor to influence of their reactivity is the type of reactive silica minerals in the reactive aggregate. Thus, constructing the kinetic parameters for reactive silica minerals involving ASR process will help with quantitative analysis of ASR.

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 18/28 Progress update: Task 4 Silica minerals undergoing ASR (Reactor method) Reactor Method Developed by Bulteel et al. (2002) Chemical method for quantitative measurement of extent of ASR Sample Preparation Polypropylene Copolymer container 20 ml of alkaline solution (0.8 M) (NaOH, KOH or NaOH+KOH) 5 grams of silica mineral (cristobalite) +0.5g of Ca(OH) 2 Placed in the oven at one of the designated temperatures (38°C, 50°C and 80°C) Stored in the oven for the period from 1 to 50 days

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 19/28 Progress update: Task 4 Silica minerals undergoing ASR (Reactor method) Treatment during Reactor Method Experiment Sound silica Degraded silica Solutions Na +, OH -, Ca 2+, H 2 SiO 4 2-, H 3 SiO 4 - Ca(OH) 2 C-S-H, C-Na-S-H Filtration of solution Acid treatment - 250ml of 0.5 M HCl Stage IStage 2Stage 3 Thermo treatment °C Stage 4

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 20/28 Progress update: Task 4 Silica minerals undergoing ASR (Reactor method) Sample No. MaterialTemperatrueSizes (mm)Solutions Conc. (M) KOHNaOHLiNO 3 1 Silica mineral*80°C0.297 to KOH0.8 2NaOH0.8 3KOH+NaOH0.4 4KOH+LiNO Silica mineral*55°C0.297 to KOH0.8 6NaOH0.8 7 Silica mineral*38°C0.297 to KOH0.8 8NaOH0.8 9Silica mineral*80°C0.075 to 0.149KOH0.8 Silica mineral* : cristobalite, opal, chalcedony, combination of minerals, reactive aggregate (Jobe sand) Test Matrix Experiments in progress

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 21/28 Objectives of related studies (Tasks 1 and 3) Task 1 (Role of lithium) To provide better understanding of the role of lithium ions Establishment of model to predict the extent of Li + ions loss from the pore solution Development of Li + ion delivery method which can potentially minimize early age losses Task 3 (Role of deicers) Strengthening the understanding of the effects of deicers on ASR Potential deliverables The model to predict the extent of Li + ions loss from the pore solution The technique to reduce the required LiNO 3 dosage for effective mitigation of ASR Advanced understanding the role of deicers in ASR

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 22/28 Task 1 Assessment of the interaction between lithium and other ions (100%) Establishment of model to predict the extent of Li + ions loss from the pore solution (100%) Providing better understanding the role of lithium (90%) Development of Li + ions delivery method which can potentially minimize early age losses of the admixture (40%) Expected completion date: Dec., 2012 Progress Update: Tasks 1 and 3

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 23/28 Task 3 Study of the formation of potassium sulfate phases in the presence of potassium acetate (100%) Evaluation of morphology and composition of ASR gels formed in the presence of different deicers (70%) Evaluation of the level of hydroxyl ions in systems exposed to different deicers (50%) Mortar bar expansion tests (80%) Expected completion date: Dec., 2012 Progress Update: Tasks 1 and 3

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 24/28 Progress update - Model for determining the loss of lithium ions due to cement hydration- Verification of the model equation (data from Kim and Olek (2012), Bérubé et al., CCR, Vol. 34 (2004), pp and Diamond, CCR, Vol. 29 (1999), pp ) Plot of measured vs. predicted concentration of Li + ions (3 different sets of data, 5 different cements, 4 different w/c and 8 different lithium dosages

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 25/28 Progress update - Role of deicers - Mortar bar expansion test (Modified ASTM 1260) Three types deicers 23% NaCl, 25% MgCl 2, 28% CaCl 2 Type I high alkali cement (Na 2 O eq = 1.04%) Two types fine aggregates Non-reactive: Ottawa sand Reactive: Jobe sand W/C=0.47

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 26/28 Progress update - Mortar bar expansion tests (1/3)- Specimens immersed in DI water, NaOH and NaCl exhibit more or less same expansion (less than 0.02% at 14 days) Specimens in CaCl 2 show some expansions even in non-reactive aggregate Specimens in MgCl 2 show some shrinkage up to 2 days and then slightly expand Overall, all specimens exhibited less than 0.1% of expansion at 14 days

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 27/28 Progress update - Mortar bar expansion tests (2/3)- Specimens immersed in NaCl and NaOH exhibit significant expansion caused by ASR Specimens in CaCl 2 also expand but the level of expansion is much lower than those in NaCl and NaOH Specimens in MgCl 2 also show some shrinkage

Prepared by T.H. Kim, J. Olek, Y. C. Chiu, N. Whiting and T. West for the FHWA ASR TWG meeting, Austin, TX, May 23, 2012 Slide 28/28 Progress update - Mortar bar expansion tests (3/3)- NaCl clearly affects the expansion of reactive mortar specimens, which indicate the acceleration of ASR Reactive mortar specimens in CaCl 2 and DI water show higher expansion than non- reactive mortar specimens in CaCl 2 Up to 6 days, expansions of specimens immersed in MaCl 2 does not show clear difference between reactive and non-reactive mortar specimens