Claims:CLAIMS

We claim

1. Eco friendly Paver blocks based on geo- polymerization technology made by replacing the cement as a binding agent with the combination of geo-polymers like Sodium silicate and sodium hydroxide solutions.

2. In order to prepare 1 cum of concrete for the blocks as claimed in claim 1 preferably Aggregate <12.5mm - 990 Kg/m3, Fly ash - 570 Kg/m3, NaOH (14 Molarity) - 81.4 Kg/m3, Na2SiO3 - 203.5 Kg/m3, Water- 57 Kg/m3 is used.

3. In order to prepare the paver blocks as claimed in claim 1:
a) The fresh concrete as claimed in claim 2 is poured in paver block moulds;
b) Then moulds are kept in oven for 48 hours at 90o C temperature;
c) After 48 hours of heat curing, the paver blocks are removed from moulds.
, Description:FORM 2
THE PATENT ACT 1970
(39 OF 1970)
AND
The patent rules, 2003
COMPLETE SPECIFICATION
(See section 10: rule 13)

1. TITLE OF INVENTION
Eco friendly Paver block

2 APPLICANTS

Name Nationality Address
Abhay Tawalare Indian Department of Civil Engineering,
Visvesvaraya National Institute of Technology Nagpur,
South Ambazari Road, Nagpur-440010
S. Durga Vikas Indian Department of Civil Engineering,
Visvesvaraya National Institute of Technology Nagpur,
South Ambazari Road, Nagpur-440010

3. PREAMBLE TO THE DESCRIPTION

COMPLETE
Following specification particularly describes the invention and the manner in which it is to be performed.

4. DESCRIPTION

Technical field of invention:
The present invention relates to the field of Civil engineering and specifically to the composition of paver blocks. More particularly relates to a method for replacing the cement as a binding agent with the combination of geo-polymers like Sodium silicate and sodium hydroxide solutions in order to produce eco-friendly Paver blocks based on the geo-polymerization technology.

Prior art:

The paver blocks are used for footpaths of roads and yards of buildings. Traditionally these are manufactured by using Cement, Aggregates, flay ash and sand. Paver blocks or pavement bricks serve chiefly as to provide artificial facings of outdoor paths, surfaces of footways and roads. Paver blocks are generally made of concrete with different geometrical shapes, among which the most common is the rectangular design.

There are many interlocking pavers available in the market. They are available in different shapes, sizes and made of different materials. Common building materials are concrete and clay, and by adapting different manufacturing methods pavers of various physical properties can be achieved. For example, pressing the dry concrete mix into moulds rather than pouring a wetter mix results in their 8000+psi compressive strength, making concrete paving stones a more durable choice than clay bricks or poured in place concrete.

Installation of interlocking pavers starts with a compacted stone sub-base and a levelling bed of sand, pavers of desirable size, shape and material. Instead of connecting the pavers by pouring grout between the joints, as one would with tiles, sand particles are spread over the pavers and tamped down. The sand stabilizes the interlocking pavers yet allows for some flexibility. This type of pavement will absorb stress such as small earthquakes, freezes and thaws, and slight ground erosion by shifting each paver slightly. Therefore they are less likely to crack or buckle like poured cement.

Cement has long been a standard building material. Over the years, various modifiers have been developed for cement based concrete formulations to provide particular properties or advantages, such as rapid curing; Compatibility with or resistance to certain materials; and varying strengths. However, modified cement based concrete formulations frequently result in products with undesirable properties

For example, a cement based concrete formulation which initially cures rapidly results in a final product with a lower strength, whereas a higher strength cement based concrete formulation lacks sufficient early strength and therefore cannot be de-moulded (removal of the mould from the cement without slumping, sagging, or deforming) for substantial periods of time.

In addition, a key disadvantage of cement based concrete formulations is shrinkage of the resulting concrete. Shrinkage is a time dependant decrease in concrete volume compared with the original placement volume of concrete. Shrinkage results from physical and chemical changes that occur in the paste fraction of concrete. The two principal types of shrinkage are plastic and drying shrinkage. Plastic shrinkage occurs while concrete is in the plastic state. Drying shrinkage occurs after concrete has reached initial set. Technically, drying shrinkage will continue for the life of the concrete, but most shrinkage occurs within the first 90 days after placement.

Moreover, due to the increasing environment concerns, however, there has been a upward demand on eco-friendly permeable paving materials, which provide water permeable properties as well as strength for use as paving materials. Permeable eco-friendly paving materials allow moisture to filter through and replenish underground water tables and other water sources. It also helps to drain water into the ground and relieve stress on over taxed storm water systems during high rain conditions.

Recently, geo-polymers have been developed as a potential alternative to cement based concrete formulations as they are also eco-friendly. The term "geo-polymer" was originally used by Josef Davidovits (Davidovits, J (1994) "High Alkali Cements for 21st Century Concretes, in Concrete Technology, Past, Present and Future", Proceedings of V. Mohan Malhotra Symposium, Editor: P. Kumar Metha, ACI SP144,383397) who proposed that an alkaline liquid could be reacted with silicon and aluminium in a source material of geological origin, or in by-product materials such as fly ash and rice husk ash, to produce binders. Because the chemical reaction that takes place is a polymerisation process, he coined the term 'geo-polymer' for these binders. Geo-polymers are members of the family of inorganic polymers.

In order to overcome the shortcomings of the prior art, the present utility model provides for using the combination of the geopolymers as a binding agent instead of the cement to provide the eco-friendly paver blocks.

The present disclosure addresses problems associated with existing binding agent in the paver blocks production systems, including those mentioned above, and provides a level of transparency and economic advantage. For this reason, it is believed to constitute progress in science and the useful acts, for which Letters Patent are hereby expressly requested.

Object:

1. The primary object of the present invention is to provide a method for replacing the cement as a binding agent with the combination of geo-polymers like Sodium silicate and sodium hydroxide solutions in order to produce eco-friendly Paver blocks.

2. Other object of the present invention resides on the fact of providing an improved eco-friendly binding material having an outline different from the known types.

3. Another object of the present invention is to reduce the dependency on the cement as a binding material as the cement manufacturing causes lot of carbon emission.

4. Another object of the present invention is to provide the system for the production of the paver block which is ready to use after 48 hours, while by traditional method the paver blocks are ready after 28 days thus saving the time.

5. Another object of the present invention is to provide an better quality control in the production of the paver blocks as in the traditional method manufacturer can reduce the curing days if sufficient curing space is not available which affects the strength of block.

6. Yet another object of the present invention is to decrease the weight of paver block by 20% than the paver blocks produced by the conventional method.

Other objects, features and advantages will become apparent from detail description and appended claims to those skilled in art.

STATEMENT:
Accordingly following invention relates to methods for replacing the cement as a binding agent with the combination of geo-polymers like Sodium silicate and sodium hydroxide solutions in order to produce eco-friendly Paver blocks based on the geo-polymerization technology. Traditionally these are manufactured by using Cement, Aggregates, flay ash and sand. In the present invention the cement is replaced as a binding material and geopolymer are used which is a combination of sodium silicate (Na2SiO3) solution and sodium hydroxide (NaOH) solution. Geopolymer is environment friendly sustainable material. The pavements blocks are ready to use after the 48 hours in comparison to the blocks obtained by conventional methods which used to require 28 days. The pavement blocks produced by this method fulfils all the standard parameters like compressive strength, abrasion test, water absorption and flexure strength which is been set as per IS 15658(2006) code requirements. The compressive strength is 45 MPa, Abrasion is 5555 mm3 5000 mm3, Water absorption is 4.8% and the Flexure strength is 2.24 MPa.

Detailed description:
The present invention relates to a methods for replacing the cement as a binding agent with the combination of geo-polymers like Sodium silicate and sodium hydroxide solutions in order to produce eco-friendly Paver blocks based on the geo-polymerization technology.

In the embodiment of the present invention relates to the method to produce 1 cum of concrete the following proportion of material mix is used.

Aggregate
<12.5mm
Kg/m3 Fly ash
Kg/m3 NaOH
(14 Molarity)
Kg/m3 Na2SiO3
Kg/m3 Water Kg/m3
990 570 81.4 203.5 57

This fresh concrete is poured in paver block moulds. Then moulds are kept in oven for 48 hours at 90o C temperature. After 48 hours of heat curing, the paver blocks are removed from moulds. The moulds are tested for compressive strength, abrasion test, water absorption and flexure strength as per IS 15658 (2006) code requirement.

The test results are as follows,
Test Our Results IS code permissible ranges
Compressive strength test 45 MPa 30 MPa to 55 MPa
Abrasion test 555 mm3 5000 mm2 1000 mm3 per 5000 mm2
Water absorption test 4.8% < 6 to 7 %
Flexure strength test 2.24 MPa 2 MPa to 7 MPa

Additional advantages and modification will readily occur to those skilled in art. Therefore, the invention in its broader aspect is not limited to specific details and representative embodiments shown and described herein. Accordingly various modifications may be made without departing from the spirit or scope of the general invention concept as defined by the appended claims and their equivalents.

Adv. Swapnil Gawande (IN/PA/1587)

CLAIMS

We claim

1. Eco friendly Paver blocks based on geo- polymerization technology made by replacing the cement as a binding agent with the combination of geo-polymers like Sodium silicate and sodium hydroxide solutions.

2. In order to prepare 1 cum of concrete for the blocks as claimed in claim 1 preferably Aggregate <12.5mm - 990 Kg/m3, Fly ash - 570 Kg/m3, NaOH (14 Molarity) - 81.4 Kg/m3, Na2SiO3 - 203.5 Kg/m3, Water- 57 Kg/m3 is used.

3. In order to prepare the paver blocks as claimed in claim 1:
a) The fresh concrete as claimed in claim 2 is poured in paver block moulds;
b) Then moulds are kept in oven for 48 hours at 90o C temperature;
c) After 48 hours of heat curing, the paver blocks are removed from moulds.

Adv. Swapnil Gawande (IN/PA/1587)

ABSTRACT

The present invention relates to a method for replacing the cement as a binding agent with the combination of geo-polymers like Sodium silicate and sodium hydroxide solutions in order to produce eco-friendly Paver blocks based on the geo-polymerization technology. Unlike the conventional method for producing pavements blocks, the new procedure neither uses cement as a binding component and nor requires the long period of curing time for the process thus having significant environmental and ecological benefits.