Waste and Marble Waste Variations on the Compressive Strength and Permeability of Porous Concrete

Development in supporting an area causes many undeveloped areas to become built up, reducing the ability of the soil to absorb rainwater, so that it flows on the ground surface and causes flooding.Handling flooding due to reduced green open land is one of them by using porous concrete in built-up areas. Porous concrete can drain water from the surface into the ground. This study aims to determine the mixture variation on the compressive strength and permeability values of porous concrete. This research uses the ACI522R-10 method with several variations of added materials. The volume addition of additives was determined by experimental method. The test results show that the compressive strength value of porous concrete shows an increase with age. The average compressive strength in mixture 2 with 40% granite waste and 4% marble waste variation resulted in 11.58 MPa.Permeability testing results that meet the requirements of ACI-522R-10 in mixture 1 with a variation of 20% granite waste and 4% marble waste. The use of granite waste with a high percentage increases the compressive strength of concrete but for the permeability value obtained by the variation of marble waste with a small percentage. Research obtained variations that can be used in the manufacture of environmentally friendly beporous concrete by utilizing waste.


Introduction
The increasing population growth in urban areas causes a lot of land that should be green open area including water catchment areas, not functioning properly [1].According to Ministerial Regulation No. 5/2008 Urban Green Open Space consists of built-up space and open space.Built-up space consists of 40% residential with 80% multi-story building construction and 20% non-residential with 90% multistory building construction [2].Public green spaces in urban areas still do not meet the minimum requirement of 20% of the total area to be provided.
One of the methods that can be done in the field of construction to solve this problem is to use environmentally friendly construction using porous concrete [3].Porous concrete is a solution for the use of environmentally friendly construction.The concrete has pores that can be traversed by water which can be applied to decompose water discharge on road surfaces, reduce the amount of runoff water, and can infiltrate water into the soil [4].
Porous concrete is composed of two main elements: cement and coarse aggregate [6].The nonutilization of fine aggregate results in porous concrete having voids in its structure [6].Porous concrete requires permeability testing to determine the water absorption process [7].The production of concrete can have an environmental impact, that is, the use of natural resources that continues to cause exploitation of nature so waste innovation is needed to overcome the impact of natural exploitation.So in concrete research, technological innovation is needed in its constituent materials [8].
Granite waste has coarse grains and a harder density, which is an igneous rock derived from the residue of ceramic manufacturing [9].The addition of granite waste as a gravel substance in concrete mixtures can increase its compressive strength [10].Granite waste is used as gravel in concrete mixes because it is relatively easy to find so that it can reduce production costs and is one of the solutions for 1317 (2024) 012011 IOP Publishing doi:10.1088/1755-1315/1317/1/012011 2 utilizing material waste so that natural resources are maintained [11].Marble waste used as an additive is waste produced from the processed marble stone industry.The characteristics of marble waste which are fine grains can be used as an admixture to cement [12].
Concrete innovation in construction requires mixed materials to support the compressive strength [13].This concrete mixture uses a mixture of granite stone waste as a substitute for coarse aggregate (gravel) and marble waste as a substitute for cement is an alternative to environmentally friendly materials in porous concrete mixtures which will be evaluated for quality based on compressive strength testing and permeability testing to determine good permeability in accordance with the mix design that has been made [7].This research aims to provide solutions to environmental problems caused by material waste and produce environmentally friendly and good quality concrete compositions [8].Environmentally friendly concrete is expected to reduce waste problems for use in building construction.

Research Methods
The research used in this study used experimental methods.This research was carried out in the Materials Laboratory of the Faculty of Engineering and the Basic Construction Laboratory of Civil Engineering, at Universitas Sebelas Maret.In research, several stages are carried out starting with the preparation stage, that is preparing tools and materials.The materials needed in porous concrete mixtures include Dynamic brand PCC cement, water cement ratio of 0.2, maximum gravel 20 mm, granite waste, and marble stone waste.The material that has been collected is then tested to determine the characteristics of each material.Table 1 presents material testing data that will be used in this research.The implementation of research on producing porous concrete is divided into six stages after the preparation stage, which are as follows: inspection of mixed materials by good quality standards, making a mix design with the addition of granite waste and marble waste innovations, stages of treatment on concrete, and tests carried out, that is compressive strength and permeability tests.
The concrete mix design calculation for producing test specimens refers to ACI 522R-10 Report on Pervious Concrete with porous concrete having a slump value close to zero [14].The quality of concrete used in the mixture is K-175.The addition of the percentage of marble waste to the weight of cement was 4% and 8%, while the addition of granite waste based on the comparison showed a percentage of 20% and 40% to the coarse aggregate material.The material composition for making specimens with a mold measuring 10 cm x 20 cm is presented in Table 2.The next stage is the production of the specimens.The specimen in this research was a cylinder measuring 10 cm x 15 cm.Each variant has 3 specimens so there are 15 specimens.The next stage is the production of the test specimens with a concrete mixer [15].The process after making test specimens is curing the concrete to prevent large amounts of water loss and maintain the humidity so that the concrete can reach the planned compressive strength [8] [17].
The porous concrete testing includes compressive strength and permeability.Compressive strength testing is carried out at the age of 7 days, 14 days, and 28 days specimens.According to SNI 03-1974-1990 [18] the compressive strength of concrete can be calculated with equation 1 as follows: Information fc' = compressive strength of concrete cylinder (MPa) P = Maximum compressive load (N) A = compressive cross-sectional area (mm 2 )

Figure 2. Compression testing machine
Permeability value testing is carried out to determine the ease with which water passes through concrete so that the factors that influence the permeability value are the cement water factor in the mixture, environmental conditions, and the water properties of the cement [6].To find the permeability value, equation 3 can be used.

Compressive Strength Testing
The addition of granite and marble waste to concrete with several variations in composition requires compressive strength testing to determine the quality of the concrete.The test results for compressive strength values are presented in Table 4.  Compressive strength testing aims to measure and determine the strength of concrete against compressive forces.Table 4 and Figure 5 show the results of testing the compressive strength of concrete at 7 days and it was found that the addition of granite and marble waste increased the strength of the concrete compared to normal concrete without additives.The concrete variation that had the highest compressive strength value in the 7-day age test was concrete with a variation of 40% granite waste and 4% marble waste with a compressive strength value of 6.68 MPa.

Figure 5. The 14-day concrete compressive strength test results
Figure 5 shows the results of testing the compressive strength of concrete aged 14 days and it was found that the highest increase in compressive strength occurred in concrete with a variation of 40% granite waste and 4% marble waste with a value of 11.4 MPa.

Figure 6. The 28-day concrete compressive strength test results
Figure 6 shows a graph of the compressive strength test results for concrete aged 28 days and it was found that the highest compressive strength value for porous concrete was in the B2 variation (40% Granite and 4% Marble Powder) of 11.58 MPa.
The test results of the overall age of the concrete in Table 4 and Figure 7 show an increase as the age of the concrete increases.The lowest average compressive strength value for the BN (Normal Concrete) variation is 9.61 MPa and the highest average compressive strength for porous concrete is the B2 variation (40% Granite and 4% Marble Powder) at 11.58 MPa.Concrete mix with 40% granite waste content gave the highest increase in compressive strength value of concrete, however, the highest increase in strength value occurred with the addition of marble waste with a low percentage, namely 4%.From the BN mixture to the B4 mixture, the greater the compressive strength obtained.This shows that the average compressive strength results are greatly influenced by the comparison of the percentage addition of variations in granite waste.

Figure 7. Overall concrete compressive strength test
Based on the results of testing the compressive strength of porous concrete as explained above, it is known that the addition of granite waste causes an increase in compressive strength, where the granite waste is used as an additional material in coarse aggregate [10].Granite has coarse grain characteristics and has a harder density [18].The advantage of using it is that apart from getting high compressive strength, it can also utilize waste to reduce the use of fresh materials and is more economical [19].Granite waste has a low level of abrasion so that granite waste can be used as a partial substituent for coarse aggregate.Granite waste has the bearing capacity for the compressive strength of concrete so that the concrete can have higher compressive strength [9].The addition of marble waste as an additive to cement provides low variation in results.Marble powder based on its characteristics is more appropriate for use as a filler material than a substitute for cement [13].Using marble powder in concrete provides advantages because its fine grains can fill the spaces between aggregates, make the concrete more cohesive, and increase the density of the concrete.The use of marble powder in concrete provides double benefits, apart from reducing the impact of waste on the environment, it also produces concrete with better mechanical properties [20].

Permeability Testing
Factors that influence permeability are the cement water factor of the porous concrete mixture, environmental conditions, and the properties of the cement.Permeability testing can be carried out using the falling head meter principle, starting with placing the specimen in the middle, filling it with water, then opening the water tap and counting the time the water flows using a stopwatch [6].
The results of permeability testing of test objects carried out by researchers and located at the Basic Construction Laboratory of Civil Engineering, Sebelas Maret University can be seen in Table 5.The effect of pore filling on permeability values is quite significant.From the results of the research above, it can be seen that porous concrete without pore filling has high permeability and absorption rates because there are no blockages in porous concrete so water can escape properly.The permeability value of the porous concrete mixture will affect the ability of the porous concrete to absorb water that falls on its surface [21].The use of granite and marble waste in pore concrete provides voids caused by the size of the waste so that it can pass water.

Conclusion
This research uses the addition of granite waste with a percentage of 20% and 40% as coarse aggregate and replacing some of the cement with marble waste at 4% and 8%.The highest compressive strength value at 28 days was 11.58 MPa with the addition of a high percentage of granite waste increasing the compressive strength of the concrete.The variation that produces the highest compressive strength is the one with the lowest percentage of added marble waste, this is because marble is better used as a filler rather than as cement.
In testing the permeability values, it was found that the concrete variation that met the requirements was the variation with the addition of 20% granite waste and 4% marble waste.This variation can release the best cavity-filling water to use.The percentage of added materials affects the pores in the concrete.

Suggestion
Based on the tests and discussions that have been carried out, it is recommended that further researchers conduct research regarding the properties of marble waste in concrete mixtures.Apart from that, it is necessary to increase the variety of waste materials in the use of environmentally friendly porous concrete because it can pass water as a means of groundwater conservation.

Figure 3 .
Figure 3. Permeability testing According to the National Ready Mixed Concrete Association (NRMCA, 2011) and the American Concrete Institute (ACI 522R -10) porous concrete has a minimum permeability value and a maximum permeability value as in table 3.

Figure 4 .
Figure 4.The 7-days concrete compressive strength test results

Table 2 .
Mix design variations

Table 5 .
Permeability test results of porous concreteBased on Table5, it is found that the use of the BN (Normal Concrete) variation which provides a permeability value of 1.518 cm/s does not meet the requirements set by (NRMCA, 2011) and (ACI 522R -10) (ACI Committee, 2010).In the variation of adding granite waste and marble waste from a mixture of B1 to B4, the highest permeability value was obtained, namely variation B4 (20% Granite and 8% Marble Powder) of 1.906 cm/s and the lowest permeability value was variation B1 (20% Granite and 4% Powder Marble) of 1.21 cm/s.Variation B1 does not meet the requirements set by (NRMCA, 2011) but meets the requirements of (ACI 522R -10).