Porous concrete is made using large aggregates with little to no fine aggregates. The concrete paste then coats the aggregates and allows water to pass through the concrete slab. Porous concrete is traditionally used in parking areas, areas with light traffic, residential streets, pedestrian walkways, and greenhouses. It is an important application for sustainable construction and is one of many low impact development techniques used by builders to In the presence of clayey soil, water can be percolated through providing borehole at every 1-2km with the help of drainage system. Water can be filtered and stored as fresh water below the ground. We can also give direction to water specifically according to need. By providing certain angle to the flaky aggregate water which gets drained will make its way to the slope going down towards the sewer line or any other drainage arrangement. This could be useful where soil strata have less water absorption capacity. INTRODUCTION Porous concrete (also called porous concrete, Porous concrete, no fines concrete and porous pavement) is a special type of concrete with a high porosity used for concrete flatwork applications that allows water from precipitation and other sources to pass directly through, thereby reducing the runoff from a. Porous concrete is made using large aggregates with little to no fine aggregates. The concrete paste then coats the aggregates and allows water to pass through the concrete slab. Porous concrete is traditionally used in parking areas, areas with light traffic, residential streets, pedestrian walkways, and greenhouses. It is an important application for sustainable construction and is one of many low impact development techniques used by builders to protect water quality Porous concrete is a mixture of cement, water and a particular sized coarse aggregate combined to form a Porous structural material. It has a high volume of voids, which is the factor responsible for the lower strength and its lightweight nature. Porous concrete is also called Porous concrete, zero-fines concrete and Porous concrete. • Highly porous allows rapid surface water removal • Reduces risk of flooding • Reduces freeze/thaw attack • Reduces the requirement for more expensive drainage systems • Reduces maintenance costs for stormwater management Pervious concrete has the void content range from 15% to 35% of total volume of concrete which gives higher permeability as the purpose of this concrete. but other hand, higher porosity decrease the amount of compressive strength of pervious concrete than conventional concrete. Use of fine sand at limit from 5% to 10% can give enough structural strength in pervious concrete. But further increment of sand can control the strength properties of pervious concrete The compressive strength of conventional previous is lower than 15 to 20 MPa [4]. But with use of modifications in coarse aggregates can increase strength in range of 12 to 14% than conventional compressive strength Porous concrete is mostly used in non-pavements applications, limited use in pavements applications. This assignment purpose is to assess the suitability for Porous concrete to be used for the construction of road pavements. This will include investigation of current literature on the topic and conducting standard concrete testing on Porous concrete and conventional concrete to determine and evaluate their properties. With the help of tested data a conclusion is made on the usefulness of Porous concrete pavements and it may be determined that further testing is required. CONCLUSION There was a considerable difference in the compressive strength between the concrete samples but this does not affect the outcome as it was the relationships between the characteristics that were assessed. The relationships showed that Porous concrete acts in a manner similar to what was found in the conventional concrete sample. A major difference found was that the Porous concrete deformed more than the conventional sample before failure. This shows that a Porous pavement has the ability to deform under the loading of traffic. The deformation should not affect the performance of the pavement providing its capacity is not exceeded. Porous concrete is a viable material that has the potential to replace the use of traditional concrete pavements in situations where heavy traffic is limited, such as car parks, residential streets and driveways. More widespread applications may be possible if methods of reducing the traveling that occurs within the top aggregate are found. The varying compressive strengths obtained from the different aggregate samples shows that the shape of the aggregate particles used can dramatically affect the strength of the concrete. LITERATURE REVIEW Klemas, 2015)The population in urban areas can grow so fast that stormwater drainage systems are not installed or the increase of impervious surfaces overwhelm the storm water sewage system that is in place Krishna Raju et al (1975) focused on the optimum water content for Porous concrete. It was determined that for the particular aggregate-cement ratio there is a narrow range for the optimum water-cement ratio. This water-cement ratio was imperative to gain the maximum possible compressive strength. A higher than ideal water-cement ratio would cause the cement paste to drain from the aggregate particles. Alternatively, a water-cement ratio too low would stop the cement paste from adhering sufficiently to the aggregate. When the optimum water-cement ratio was not obtained, sufficient compaction could not be achieved, further compounding the loss of compressive strength. Abadjieva et al (1997) investigated the influence of the aggregate-cement ratio on the tensile and flexural strength of Porous concrete. This study only assessed aggregate-cement ratios ranging from 6:1 to 10:1. The highest strengths were obtained with an aggregate-cement ratio of 7:1 and the strength decreased with an increasing aggregate-cement ratio. He found that the tensile and flexural strengths of Porous concrete were considerably lower than those obtained from conventional concrete, but he could not explain why the sample with the highest strength had a ratio of 7:1. Baoshan Huang(2009)[4] carried out the experiment on pervious concrete with use of latex polymer to improve the strength properties. With use of latex, natural sand and fibre they evaluated the effect of polymer modification on mechanical and physical properties of PMPC. Based on results , it was possible to produce pervious concrete mixture with acceptable permeability Objectives of the Proposed work 1. find out durability, properties of Porous concrete. 2. To conclude impact resistant of Porous concrete asphalt road. 3. To compare the properties of Porous concrete with the existing concrete roadway. 4. To find the Strength of Porous concrete. EXPERIMENTAL WORK 4.2 Test Methodology This project is focused predominantly on the use of Porous concrete as a road pavement material. As this is a comparison between Porous concrete pavements and conventional concrete pavements, there is a requirement that the tests being conducted can occur on both samples. The test procedure included the initial steps of deciding on the tests to be conducted and choosing a number of aggregate-cement ratios for the Porous concrete. This was followed by conducting the preliminary mix design and compressive strength tests on these samples to determine the mix that performed most successfully. 4.3 Concrete Tests The tests that were conducted had to provide a complete picture of all the characteristics of the concrete in both the wet and hardened state. For this reason, it was proposed that the testing incorporate aggregate testing to determine the potential effect of the aggregate shape on the performance of the Porous concrete. This was followed by conducting workability tests like the slump and compacting factor tests on the wet concrete sample. The hardened concrete tests proposed for the project were compressive strength and indirect tensile tests. This testing includes determining the void ratio and assessing the permeability of the Porous concrete. 4.4 Mix Design The mix design in this case was the determination of the ratio of aggregate, cement and water that possessed the most favorable properties. For this particular situation trial mixes were designed. The mixes were determined from previous literature and particular mixes used by some companies. There are only three constituents of Porous concrete that can be considered and varied: aggregate, cement and water content. 4.5 Conventional Concrete There was no mix design undertaken for conventional concrete, since the strength of certain mixes is readily known. This meant that no trials were required to be carried out. When conducting the tests to determine the properties of a conventional concrete. 4.6 Porous Concrete The mix designs for Porous concrete were obtained from printed articles. There were a large number of different mixes that are currently being used for a whole range of applications. Aggregate Cement Water 7 1 0.3 5 1 0.3 4.2 1 0.3 4.6 1 0.23 Table 4.1 – Mix Proportions used for Porous Trial Mixes 4.6.3 Mixing Process Figure 4.1 – Mixing of no fine concrete 4.6.5 Result and Analysis Half the samples were tested for compressive strength and indirect tensile strength at 14 days. The remaining small and large samples were tested for 28 day compressive strength. The results of those tests can be found in the table below. 14 Day Strength 28 Day Strength Aggregate- Cement- Water ratio Compressive Strength (MPa) Indirect Tensile Strength(MPa) Compressive Strength (MPa) Compressive strength of large cylinders (MPa) 8:1:0.2 4.29 1.54 3.25 6.67 4.29 3.61 6:1:0.3 6.68 1.62 7.54 5.33 7.22 7.34 4.5:1:0.3 7.34 2.29 11.72 7.62 7.78 12.88 4.8:1:0.26 8.81 1.53 6.41 5.25 8.41 6.38 Table 4.2 – The data collected from the trial mixes 4.7 Summary The Porous concrete mix design found that an aggregate-cement-water mix of 4.5:1:0.3 produced the highest compressive strength out of the different mix proportions trialed. Since the highest compressive strength was found in the 4.5:1:0.3 mix, it was used for the remainder of the testing in this project. 4.8 Sieve Analysis Sieve analysis is a method of determining the grading of a particular aggregate or a mixture of aggregates. The sieve analysis is carried out in a mechanical sieving machine to provide a more consistent result and achieve much greater accuracy. The sieves used vary in size but consecutive sieves used are smaller in aperture as you move down the stack. There are three different methods for undertaking a sieve analysis. Two wet analysis methods can be used, one with alcohol and the other with water. The third method is dry analysis, which can only be used for granular particles larger than 125 m. 4.11 Compressive Strength • The compressive strength tests are conducted to ensure a minimum strength is achieved by the particular mix. Cylinder and cube testing are methods of determining the compressive strength. Both methods of determining compressive strength will be used as it may be difficult to achieve a good result when using the cylinders. 4.13 Indirect Tensile Test The tensile strength of concrete cannot be measured directly. This leads to the need to determine the tensile strength through indirect methods. The indirect tensile test is also referred to as the ‘Brazil’ or splitting test, where a cylinder is placed on its side and broken in the compression machine. This test can also be used to determine the modulus of elasticity of the concrete sample. CHAPTER-5 RESULTS AND ANALYSIS 5.1 Compacting Factor Test Result Types Partially compacted (m1) kilograms Fully compacted (m2) kilograms Compacting Factor No-Fine concrete 10.726 11.413 0.95 Conventional concrete 13.041 13.462 0.97 Table 5.1 – Shows the Compacting Factor for all the samples of concrete used Figure 5.1 - Chart of compacting Factor for all the samples of concrete used Porous concrete is a self-compacting material and this test determines its ability to compact itself dropping from a set height. Porous concrete can be dropped from large heights and this test shows these properties by the amount of compaction obtained from simply allowing the concrete to drop. 5.2 Compressive Strength Test Result