Claims:We Claim:
1. An instrument for non-destructive measurement of the maturity of concrete and method thereof characterised by real time, non-destructive determination of the maturity and compressive strength of the concrete and similar construction materials, using single or plurality of sensors and distinctively programmed to work in synchronization with all its components in real-time and in unison, the said system comprising embedded in a casing box with a removable sealed lid (2), a power supply (13), a charging module (12) with a LED indicator (5), equipped with a battery charging port (1), a microprocessor chip ESP8266 SOC (11), connected to a Wi-Fi data logger (9) providing outputs in two ways provides output in two ways i.e. to storage hardware characterised by but not limited to a micro SD card or hard drive (10) and Cloud storage with Industry-4.0 protocol (14), single or plurality of maturity temperature digital sensors (8), connected to the microprocessor chip (11) via connectors with wires (7) to the connecting ports (6) on the said microprocessor chip (11), an output of the Wi-Fi data logger (9), typical power on (3) and reset button (4).

2. The instrument for non-destructive measurement of the maturity of concrete as claimed in claim (1) wherein the maturity temperature sensors (8) are made up of semi-conductor material characterised by silicon or germanium.

3. The instrument for non-destructive measurement of the maturity of concrete as claimed in claim (1) wherein the maturity temperature digital sensors (8) are provided with plastic reusable sleeves, which allow the sensors and its connection wire to be removed from the hardened concrete after the end of data monitoring, for reuse.

4. The instrument for non-destructive measurement of the maturity of concrete as claimed in claim (1) wherein the microprocessor chip (11) is programmed to receive the data from the maturity temperature digital sensor/s (8), record and store the various input parameters provided by the end user, store and analyse the calibration data, compare the calibration data with the data received from the sensors, generate maturity index and indicate/display and report the data in real time.

5. The instrument for non-destructive measurement of the maturity of concrete as claimed in claim (1) the connected sensor/s (8) is/are non-sacrificial (i.e., not required to be permanently embedded in concrete), installed or embedded in concrete through plastic sleeve(s), and could be removed without destruction affording reusability thereof.

6. The instrument for non-destructive measurement of the maturity of concrete as claimed in claim (1) wherein the channel/s are equipped with combinations of any digital compatible sensor/s to monitor and measure concrete parameters characterised by but not limited to temperature, humidity, moisture levels, pH levels, air content, resistivity, detection of chemicals/materials, and transmissibility,

7. The instrument for non-destructive measurement of the maturity of concrete as claimed in claim (1) wherein the connected sensor/s (8) is/are connected to the respective meter with detachable wires/cables for easy and quick removal, repairing, extensions and replacements from the meter.

8. The instrument for non-destructive measurement of the maturity of concrete as claimed in claim (1) wherein the microprocessor chip (11which is programmed to function with a range of user-defined data sampling rate, ranging between 1 reading per minute to 1 reading per 24 hours, range from 1-reading per minute up to 1-reading per 24-hours, in increment of fractional decimal values

9. A process for determination of maturity and other performance characteristics of the concrete using the maturity meter system of the present invention which comprises installing the sensors in the concrete to be examined, and obtaining the periodic readings which are stored on the memory micro SD card (10) and the Industry-4.0 enabled Cloud (14) simultaneously, comparing these readings with calibration data generated and programmed in the microprocessor chip (11), to generate real-time data to know the maturity and performance characteristics of the concrete under examination.
, Description:
FORM 2

THE PATENTS ACT-1970
(39 of 1970)

The Patent Rules, 2006

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

1. TITLE OF THE INVENTION
An instrument for non-destructive measurement of the maturity of concrete and method thereof
2. APPLICANT
Name Pune Construction Engineering Research Foundation

Nationality An Indian Company

Address 6, Srinivas Building, Patwardhan Baug
Erandwane Pune -411004 Maharashtra India

3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

Title:
An instrument for non-destructive measurement of the maturity of concrete and method thereof.
Field of Invention:
The present invention relates to an instrument (designated as iCoMM) for non-destructive measurement of the maturity of concrete and method of determination of maturity of concrete. The said maturity meter which may be single channel or multi- channel provides procedure for estimating the compressive strength would be objective and qualitative once the maturity curve is developed and adopted. The present invention also provides for the non-destructive method for establishing the compressive strength of concrete.

Background of invention:
The maturity method, often simply referred to as maturity, is a way of evaluating new concrete’s in-place strength by relating time and temperature measurements to actual strength values.
To expedite schedules, increase safety, and improve construction methods, construction teams want to know the strength of their concrete at the job site in real time. Since maturity is related to concrete strength, the maturity method is a way to accomplish this without solely relying on standard test specimens and laboratory testing.
Maturity is calculated by tracking changes in fresh concrete temperature over time. Since each concrete mix has its own strength-maturity relationship, we can use maturity to estimate the strength of that mix at any moment after placement. When we know the maturity of a certain concrete, we can use that concrete’s specific strength-maturity relationship to make a reliable estimate of its strength.
In most construction sites, field-cured concrete samples are tested to strength at various ages during the first week since concrete is poured, in order to decide on formwork removal. American Society for Testing and Material (ASTM C873) offers a test method for cast-in-place cylindrical specimens. These specimens can be removed later for measuring the compressive strength of concrete in the lab. Usually, if the concrete reaches 75% of its designed strength, the structural engineers allow for the striping of forms. The problem, however, is that only one specimen is crushed for strength estimation. This is not necessarily accurate. This method is limited to use in horizontal and thick concrete elements like slabs. In addition, the construction crew is usually on the job site while they are waiting to hear about the compressive strength result from the lab. This adds to the cost of construction and its uncertainty decreases the efficiency of the construction.
Except for specific projects, the concrete industry shows interest in the commonly used compressive strength test. This is mainly due to the upfront cost of concrete mixture calibration for maturity curves, and lack of expertise for the installation of concrete temperature sensors, data collection and analysis.
As a non-destructive testing, the concrete maturity testing method may be a reasonable candidate to fill this gap. In comparison to most on-site non-destructive technologies, the privilege that the maturity method stands on is that, the procedure for estimating the compressive strength would be objective and qualitative once the maturity curve is developed and adopted.
In the 1970s, a string of fatal construction disasters motivated engineers and researchers to refine the technique for routine construction.

In the spring of 1973, a multi-story apartment building collapsed during construction in Fairfax County, Virginia due to weak concrete. The project’s construction team had waited a full four days for the concrete to cure, then removed forms—but the concrete hadn’t yet gained enough strength and the building collapsed. The incident claimed 14 lives and injured 34 others. Five years later, 51 workers were killed when a cooling tower crashed to the ground while under construction in Willow Island, WV. Again, the structure failed because the concrete had not gained enough strength to support the loads.

The maturity method accounts for the combined effects of time and temperature on concrete strength develop¬ment. The strength of a given concrete mixture that has been properly placed, consolidated, and cured, is a function of its age and temperature history.

The maturity concept has been around for many years and has proven to be a useful tool in several specialties within the concrete industry. This is especially true among fabricators of prestressed and other prefabricated concrete products where it is essential to obtain strength information at an early date and with minimal cost.

Early research was conducted in 1951 by Saul who introduced and defined the term “maturity” as fol¬lows during his investigation on steam curing of con¬crete: “the maturity of concrete may be defined as its age multiplied by the average temperature above freezing* that it has maintained.” From this definition, he went on to develop the law of strength gain with maturity: “Concrete of the same mixture at the same maturity (measured as temperature-time) has approxi¬mately the same strength whatever combination of temperature and time goes to make up that maturity.” Over the years, Saul’s work has been confirmed and refined by other researchers

Maturity testing provides strength evaluation by the monitoring of internal concrete temperature in the field. The basis of maturity is that each concrete mixture has a unique strength-time/temperature relationship. Therefore, for concretes of a specific mixture, the same strength will develop at a given maturity value. The maturity value is the sum of the Degree Celsius-Hours from initial concrete placement to a given time during the curing process.

Based on field case studies conducted in several states, maturity can predict concrete strengths. The Iowa Department of Transportation has been using the method for several years and found it to give consistent and reproducible results. The application of computers introduces a low-cost method of analysing the strength gain that is taking place in concrete structures or pavements. This is especially of interest for pavements, where It is essen¬tial to evaluate strength at early ages in order to deter-mine the time at which they may be opened to traffic.

Two maturity functions are commonly used for computing the maturity index. The first is the Nurse-Saul equation that calculates the time-temperature factor (TTF) using the following equation:
M(t) = ? (Ta-To) ?t
where:
M(t) = temperature-time factor (TTF) at time t, Degree Celsius - Days or Degree Celsius - Hours
? t = time interval, days or hours
Ta = average concrete temperature during time interval, °C or °F
To = datum temperature at which it is assumed that concrete ceases to gain strength with time; the value of -10°C (14°F) is most commonly used.
This equation (Nurse-Saul) is the most popular pro¬cedure in use by state DOTs. When this equation is used, the concrete strength is related to the logarithm of TTF.
The other maturity function, the Arrhenius equation, is used to calculate the “equivalent age” maturity index. Equivalent age represents the equivalent duration of curing at the reference temperature that would result in the same value of maturity as the curing period at a given average temperature.
Equation 2
te = ?e-Q(1/Ta-1/Ts) ?t
where:
te = equivalent age at standard or reference temperature, days or hours
e = 2.718
Q = apparent activation energy divided by the gas constant, (E/R), °K
E = apparent activation energy, J/mole R = universal gas constant = 8.314 J/mole°K
Ta = average concrete temperature during time interval, ?t, °K
Ts = standard or reference temperature, °K
?t = time interval, days or hours
K = absolute temperature, Kelvin, °K= °C+273.15
The maturity meters in the prior art have following drawbacks.
• The maturity meters available in the prior art can be placed in the concrete formwork, no more than 3" deep (installed on the rebar) before pouring, to monitor the temperature of concrete in situ.
• Those meters have no data storage facility.
• The training cost is differently charged as the product cost does not include training.
• The other meters and its sensors are sacrificed during the measurements.
• Devices with wireless technologies have limited data range.

The main object of the present invention therefore is to provide maturity meter with single or multi-channel for non-destructive testing of concrete which provides for estimating the compressive strength which would be objective and qualitative once the maturity curve is developed and adopted.

Another object is to provide a meter and the method using said meter which will give comprehensive results, provide for ability to access the data via internet on any compatible instrument.

Still another object is to provide a meter wherein the data is logged and/or retrieved by an external wireless device in real-time with no limitation of data transmission range.

Yet another object is to provide the maturity meter and the method using the said meter for estimation of concrete strength which is reliable, quick and provides real-time indicators.

Summary of the invention:
The present invention provides an instrument for non-destructive measurement of the maturity of concrete and method thereof with single or multi-channel for Non Destructive testing of concrete using the said meter. The said meter comprises a power supply, a charging module, equipped with USB ports, a Wemos D1 Mini, connected to a Wi-Fi data logger with storage facility, single or multi sensors connected to the Wemos D1 Mini processor via suitable connector(s), output of the Wi-Fi data logger connected to the display and other conventional power on and reset buttons. All these components are connected to each other either with wire or wirelessly.

The present invention also provides a method for determination of maturity of concrete using the said maturity meter provided by the present invention.

Brief description of the drawing:
Fig. (1) shows top view of the maturity meter.
Fig. (2) shows side (A) view of the maturity meter.
Fig. (3) shows side (B) view of the maturity meter.
Fig. (4) shows schematic diagram of the maturity meter.

Detailed description of the drawings:
Following legends given in table (1) have been used in the drawing accompanying this specification to describe various components of the maturity meter provided by the present invention.

Table (1)
Legend No. Description
1. Charging Port
2. Casing
3. Power on button
4. Reset button
5. LED Indicator
6. Sensor port(s)
7. Sensor connector(s)
8. Maturity Sensor(s)
9. Wi-Fi data logger
10. Output 1 (Micro SD card)
11. Wemos D1 Mini processor
12. Charging module
13. Power supply
14. Output 2 (Cloud)

Detailed description of the drawings:

Referring to the Fig. (1) to (4) the instrument for non-destructive measurement of the maturity of concrete and method thereof with single or multi sensors provided by the present invention comprises embedded in a casing (2) a power supply (13), a charging module (12), equipped with charging port (1), a Wemos D1 Mini processor (11) (hereinafter Wemos), connected to a Wi-Fi data logger (9) which provides output in two ways i.e. to storage hardware characterised by but not limited to a Micro SD card or hard drive (10) and Cloud storage (14), single or multi maturity sensors (8) connected to the Wemos via connector(s) (7) to the connecting ports (6) on the said Wemos (11), an output of the Wi-Fi data logger (9) and other conventional power on (3) and reset button (4).

In one of the embodiments of the present invention the sensors (8) are made up of semi-Conductor material characterised by silicon or germanium.

In still another embodiment the maturity sensors (8) may be provided with Temperature sensor reusable sleeves for repetitive use of the sensors.

In yet another embodiment the Wemos (11) is programmed to receive the data from the sensors, store the calibration data, compare the calibration data with the data received from the sensors, generate maturity index and indicate the maturity point in real time.

The present invention also provides a method for determination of maturity of the concrete using the maturity meter provided by the present invention which comprises installing the sensors in the concrete to be examined, and obtaining the periodic reading which are stored on the memory card (10) and the cloud (14) simultaneously, comparing these readings with calibration data generated and programmed in the Wemos (11) to generated real time data to know the maturity point of the concrete under examination.

Working of the invention:
This method works in 3 Phase as follows:
A. Configuration:
1. On the meter
2. Search for meter ID using mobile Wi-Fi
3. Connect to meter using Wi-Fi
4. Open iCoMM Configuration Application
5. Tap on “Get” button
6. Enter the relevant details
7. Tap on “Set” button
8. “Meter Configured Successfully” dialogue box pops up
9. Now connect sensors to meter
10. Install sensors with sleeve in structural element
11. Press reset button once done
iCoMM senses time &temperature readings of concrete and transmits data on cloud using local Wi-Fi with active data connection.

B. Calibration:
Readings recorded from iCoMM are further analysed using Calibration Module
1. Open the program on PC/Laptop
2. Enter relevant details
3. Enter regime details, save and proceed
4. Check for active internet connection.
5. Wait unless maturity index gets calculated
6. Enter the strength details obtained from cube test performed on respective age.
7. Calibrate the data using all 3 types of regression options available viz. Logarithmic fit, Polynomial fit, Power-Log fit.
8. Save the details and Quit
Calibrated readings will be further used for real-time monitoring using Deployment module.

C. Deployment:
iCoMM shows real time data based on calibrated readings.
1. Open Deployment Module of program on PC/Laptop.
2. Enter the relevant details.
3. Check for active internet connection.
4. And press “Start” button
5. Wait and observe real-time strength.
6. Take decisions based on results obtained.


Advantages of the present invention.:
• Information is gathered/stored/transferred by 1- or 4- Channels meter with embedded Maturity sensors, processed by a micro-controller system, recording real-time temperature and then maturity based estimating strength of hydrating (freshly cast and subsequently setting) in-situ concrete.
• Data is logged and/or retrieved by an external wireless device in real-time.
• iCoMM Works on Data connection so no limitation of data transmission range.
• All the data is stored in cloud and end-user can retrieve the data from anywhere, where the data connection is available using software provided with iCoMM.
• Data is stored on storage hardware such as SD- card and cloud storage simultaneously. There is no loss of data.
• The data is logged without interruption, so the results are consistent and reliable.
• The maturity method based iCoMM predicts the mix-dependent actual in-place strength of concrete.
• Maturity shows local variation in strength for different structural locations, irrespective of the concrete curing regimes.
• It is reliable, quick, proven and provides real-time indicators, saves time, money and efforts.
• Concrete strength results are estimated using novel algorithm codes, collected in real-time, and results are displayed in a very user-friendly format on an android Smartphone/laptop/pad/PC.