Startup Thailand: A New Innovative Sacrificial Anode for Reinforced Concrete Structures

Severe damage reinforced concrete structures affected by corrosion are increasing. The study of prevention and protection technique play an important role to cope this urgent issue. Usage of different types of surface coatings on concrete/rebar are highly depend on workmanships of construction. Thus, sacrificial anodes are offered as one of the corrosion prevention technique. The discrete sacrificial anodes are comprise of zinc metal covered with a high alkalinity mortar which sacrifices itself to protect the corrosion of rebar. The key parameter of sacrificial anode in concrete is the activating mortar. It will help the overall cathodic reaction to efficiently protect reinforcing steel. Therefore, a new sacrificial anode was then accomplished in new activating mortar components. Two different activating mortar type have been established. This research investigated the performance of the new sacrificial anodes installed in the concrete prisms, slabs, and concrete water tanks in order to explore the corrosion prevention performance as per NACE [1], ISO [2] and ASTM standards [3-4]. This experimental study was tested on ASTM G109 [3], ASTM C876 [4] and small-scale water tank suffering from chloride-induced corrosion of the reinforcement. The performance of the anodes was determined at 28 days age and 365 days after installation to assure the activating time dependency for the mortar. The results of concrete prisms and slabs revealed that the anode polarized the rebar at a significant potential. For the water tank test results, two different concrete type were conducted with exposing chloride solution and assessed using close-interval potential mapping. The results showed a good agreement with enhance the structural durability

Low temperature heat capacity of Fe_{1-x}Ga_{x} alloys with large magneostriction

The low temperature heat capacity C_{p} of Fe_{1-x}Ga_{x} alloys with large magnetostriction has been investigated. The data were analyzed in the standard way using electron ($\gamma T$) and phonon ($\beta T^{3}$) contributions. The Debye temperature $\Theta_{D}$ decreases approximately linearly with increasing Ga concentration, consistent with previous resonant ultrasound measurements and measured phonon dispersion curves. Calculations of $\Theta_{D}$ from lattice dynamical models and from measured elastic constants C_{11}, C_{12} and C_{44} are in agreement with the measured data. The linear coefficient of electronic specific heat $\gamma$ remains relatively constant as the Ga concentration increases, despite the fact that the magnetoelastic coupling increases. Band structure calculations show that this is due to the compensation of majority and minority spin states at the Fermi level.Comment: 14 pages, 6 figure

Fe–Ga/Pb(Mg1/3Nb2/3)O3–PbTiO3 magnetoelectric laminate composites

We have found large magnetoelectric (ME) effects in long-type laminate composites of Fe–20%Ga magnetostrictive alloys and piezoelectric Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals. At lower frequencies, the ME voltage coefficient of a laminate with longitudinally magnetized and longitudinally polarized (i.e., L-L mode) layers was 1.41 V/Oe (or1.01 V/cm Oe). Near the natural resonant frequency ( ∼ 91 kHz) of the laminate, the ME voltage coefficients were found to be dramatically increased to 50.7 V/Oe (36.2 V/cm Oe)for the L-L mode. In addition, the laminate can detect a minute magnetic field as low as ∼ 2×10−12 T at resonance frequency, and ∼ 1×10−10 T at lower frequencies

Magnetostrictive and magnetoelectric behavior of Fe–20 at. % Ga/Pb(Zr,Ti)O3 laminates

The magnetostrictive and magnetoelectric (ME) properties of laminate composites of Fe–20 at. % Ga and Pb(Zr,Ti)O3 (PZT) have been studied for laminates of different geometries. The results show that (i) a long-type magnetostrictive Fe–20 at. % Ga crystal plate oriented along 〈001〉c and magnetized in its longitudinal (or length) direction has higher magnetostriction than a disk-type one; and consequently (ii) a long-type Fe–20 at. % Ga/PZT laminate has a giant ME effect, and is sensitive to low-level magnetic fields