Understanding of concrete structure: multi-scale ... multi-scale/   UNDERSTANDING OF CONCRETE STRUCTURE:

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  • Ippei MARUYAMA, NAGOYA UNIV.

    UNDERSTANDING OF CONCRETE STRUCTURE: MULTI-SCALE OBSERVATIONS AND MODELING IPPEI MARUYAMA NAGOYA UNIV. SYSTEMIZATION OF CONCRETE SCIENCE AND TECHNOLOGY THROUGH MULTI-SCALE MODELING 13RD JULY, 2015

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  • Ippei MARUYAMA, NAGOYA UNIV.

    MULTI-SCALE PROBLEM Long-term service of concrete structures is required by many

    reasons. (Economical, Environmental (CO2, saving materials))

    Maintenance / Aging management is required.

    The knowledge of Maintenance / Aging management should contribute to the design of new structures.

    In matured society, extension of service life of concrete structure is more important rather than re-build the structures. Especially in case of Japan, which is under decreasing in population.

    Sensing and monitoring are applied to many structures for evaluating structural performance, damage or deterioration of reinforced concrete members.

    2

  • Ippei MARUYAMA, NAGOYA UNIV.

    NEW PROBLEM OBSERVED IN MONITORING : ONAGAWA NPP

    Onagawa NPP-3 was suffered from several (relatively large) earthquakes. Based on the monitoring results of accelerometer or velocimeter, modes of vibration are evaluated and natural frequencies were obtained.

    Even though, all the earthquakes were found that they did not affect the structural cracking of quake resisting walls according to the design basis evaluation, 1st mode natural frequency of structure was decreased.

    0 2 4 6 8 100

    0.2

    0.4

    0.6

    0.8

    1

    Rel

    ativ

    e na

    tura

    l fre

    quen

    cy (T

    /To)

    Years after constructionSimulation results of nuclear power plant building 2 and 3 in Onagawa site of Tohoku electric power company, Nuclear and Industrial Safety Agency Japan, 2011 (in Japanese). 3

  • Ippei MARUYAMA, NAGOYA UNIV.

    NEW PROBLEM OBSERVED IN MONITORING : 8-STORY BRI BLDG

    Building Research Institute, they have 8-story steel-reinforced concrete building. It contains many kinds of monitoring system and using the monitoring data, the change in natural frequency has been detected.

    The trend is very similar to that of Onagawa NPP-3.

    0 2 4 6 8 100

    0.2

    0.4

    0.6

    0.8

    1

    Rel

    ativ

    e na

    tura

    l fre

    quen

    cy (T

    /To)

    Years after construction

    Onagawa-1 NPP BLI-building

    T. Kashima, Y. Kitagawa, Dynamic characteristics of a building estimated from strong motion records using evolution strategy, J. Struct. Const. Eng. AIJ, 602 (2006) 4

    Onagawa NPP-3

  • Ippei MARUYAMA, NAGOYA UNIV.

    NEW PROBLEM OBSERVED IN MONITORING : 8-STORY BLDG

    It is also confirmed that this decreasing trend is observed between earthquakes. During the every earthquakes, there is no damage, except for Tohoku-earthquake.

    L. Li, A. Nakamura, T. Kashima, M. Teshigawara, EARTHQUAKE DAMAGE EVALUATION OF AN 8-STORY STEEL-REINFORCED CONCRETE BUILDING USING Sa-Sd CURVES, J Struct Constr Eng, 79 (2014) 1107-1115. 5

  • Ippei MARUYAMA, NAGOYA UNIV.

    POSSIBLE IMPACT - For high-rise building, the decreasing of natural frequency

    of building may cause to resonance, even wide range of frequency is considered in design state. System controlling is needed for compensating large seismic deformation.

    - For nuclear power plant, supporting system is important. Resonance with piping system, cable system, or other facilities introduced in the plant are important issue. 2nd mode of structure might arise the problem. Aging management is important.

    - Fundamental mechanism understanding and prediction is needed for aging management.

    6

  • Ippei MARUYAMA, NAGOYA UNIV.

    PASTE-AGGREGATE-CONCRETE

    PASTE C-S-H, Mesoscale structural compaction

    + Dehydration of C-S-H from interlayer and

    resultant strength change

    Strength Shrinkage

    Aggregate

    Mineralogical composition

    Shrinkage Stiffness, Strength

    Damage in concrete

    Concrete stiffness

    Concrete shrinkage

    Stiffness

    Cracking in member

    Stiffness of member 7

  • Ippei MARUYAMA, NAGOYA UNIV.

    SHRINKAGE OF PASTE

    8

  • Ippei MARUYAMA, NAGOYA UNIV.

    IRREVERSIBLE SHRINKAGE

    10

    0 0.2 0.4 0.6 0.8 1-0.006

    -0.005

    -0.004

    -0.003

    -0.002

    -0.001

    0

    Relative humidity (p/p0)

    Stra

    in (m

    /m)

    N55

    I. Maruyama, Origin of Drying Shrinkage of Hardened Cement Paste: Hydration pressure, Journal of Advanced Concrete Technology, Vol. 8, No. 2, pp.187-200, 2010.6

  • Ippei MARUYAMA, NAGOYA UNIV.

    MECHANISM OF SHRINKAGE IN FIRST DESORPTION

    11

    -0.016

    -0.014

    -0.012

    -0.01

    -0.008

    -0.006

    -0.004

    -0.002

    0

    0 0.5 1 1.5 2

    Shr

    inka

    ge s

    train

    (x10

    -6)

    Statistical thickness of adsorption (nm)

    - Where disjoining pressure acts? - Long-term shrinkage is always liner function of statistical

    thickness of adsorption.

    0 0.2 0.4 0.6 0.8 1-0.006

    -0.005

    -0.004

    -0.003

    -0.002

    -0.001

    0

    Relative humidity (p/p0)

    Stra

    in (m

    /m)

    N55

    I. Maruyama, Origin of Drying Shrinkage of Hardened Cement Paste: Hydration pressure, Journal of Advanced Concrete Technology, Vol. 8, No. 2, pp.187-200, 2010.6

  • Ippei MARUYAMA, NAGOYA UNIV.

    DIFFERENT SHRINKAGE WITH DIFFERENT PRE-DRYING

    12

    SDSXX: Slowly (more than 1 year ) Dried Sample at XX %RH.

  • Ippei MARUYAMA, NAGOYA UNIV.

    DIFFERENT SHRINKAGE WITH DIFFERENT PRE-DRYING -Shrinkage of paste with different RH pre-drying showed different shrinkage strain = different irreversible shrinkage. - Shrinkage 40-98%RH shows good correlation with incremental statistical thickness of adsorption at 40-98% RH.

    13

    Maruyama, I., G. Igarashi and Y. Nishioka (2015). "Bimodal behavior of C-S-H interpreted from short-term length change and water vapor sorption isotherms of hardened cement paste." Cement and Concrete Research 73 0 158-168.

  • Ippei MARUYAMA, NAGOYA UNIV.

    SHRINKAGE IN LOW RH AREA - Shrinkage strain under 40% RH is high correlation with water vapor BET surface area of hcp.

    14

    3l S

    l E =

    S

    Maruyama, I., G. Igarashi and Y. Nishioka (2015). "Bimodal behavior of C-S-H interpreted from short-term length change and water vapor sorption isotherms of hardened cement paste." Cement and Concrete Research 73 0 158-168.

  • Ippei MARUYAMA, NAGOYA UNIV.

    15

    Sorption potential contour

    - From the 1H-NMR experiment, matured cement paste does not contain capillary water. (Muller et al.)

    - In the interlayer, sorption potentials from both planes are overlapped. Sorption potential is higher in interlayer.

    WHERE IS WATER?

    1) Muller et al., The Journal of Physical Chemistry C, Vol.117, No.1, pp.403-412 (2013)

    2) G. Igarashi, 2014, Behavior of Water Vapor Adsorption on Calcium Silicate Hydrate in Portland Cement Pastes, dissertation, Nagoya university.

    *1

    *2

  • Ippei MARUYAMA, NAGOYA UNIV.

    TWO POSSIBILITY 90 RH

    16

    A: Gel and constant layer disctance

    B: Movable layer distance *2

    Feldman model

    2) Maruyama, I., G. Igarashi and Y. Nishioka (2015). "Bimodal behavior of C-S-H interpreted from short-term length change and water vapor sorption isotherms of hardened cement paste." Cement and Concrete Research 73 0 158-168.

    1) R.F. Feldman, Sorption and length-Change scanning isotherms of methanol and water on hydrated portland cement in: Fifth international symposium on the chemistry of cement, Tokyo, 1968, pp. 53-66.

    *1

    3) G. Igarashi, 2014, Behavior of Water Vapor Adsorption on Calcium Silicate Hydrate in Portland Cement Pastes, dissertation, Nagoya university.

    *3

  • Ippei MARUYAMA, NAGOYA UNIV.

    SHRINKAGE OF AGGREGATE

    17

  • Ippei MARUYAMA, NAGOYA UNIV.

    SILICIOUS AGGREGATE - Aggregate in concrete shows

    considerable shrinkage and it affects on shrinkage of concrete (Roper, PCA, 1960) as well as other physical properties of concrete.

    - Sedimentary silicious rocks are used in Japan, but they show wide range in properties.

    - Various and typical rocks are investigated.

    18

    Submitted to Construction and Building Materials

  • Ippei MARUYAMA, NAGOYA UNIV.

    SHRINKAGE OF AGGREGATE - Short-term length- change isotherms with orthogonal 3-

    directions were recorded.

    19

    Submitted to Construction and Building Materials

  • Ippei MARUYAMA, NAGOYA UNIV.

    COMPONENTS OF AGGREGATE - Powder XRD / Rietveld analysis was conducted.

    20

    Submitted to Construction and Building Materials

  • Ippei MARUYAMA, NAGOYA UNIV.

    CORRELATION - Strong correlation is obtained between amount of chlorite

    and shrinkage strain. - Weathering and resultant chlorite, not Illite or Sericite,

    cause shrinkage in matrix, and produce macroscopic shrinkage of aggregate.

    21

    Submitted to Construction and Building Materials

  • Ippei MARUYAMA, NAGOYA UNIV.

    INTERACTION BETWEEN AGGREGATE AND MATRIX

    22

  • Ippei MARUYAMA, NAGOYA UNIV.

    DAMAGE IN CONCRETE - Heterogeneous behaver between coarse aggregate and

    matrix must be observed. - Damage behavior is detected by Digital Image Correlation

    Method (DICM).

    23 Max. principle strain dist. Results of fluor-epoxy intrusion method

    I.Maruyama,H.Sas