Water Cement Research Articles

Resistance of Concrete to Na<sub>2</sub>SO<sub>4</sub> Freeze-Thaw Cycles and Failure Mechanism Analysis

Rapid freeze–thaw cycle experiments were carried out on concrete specimens with 0.4, 0.5, and 0.6 water–cement (w/c) ratio in 0% (tap water), 1%, and 5% Na2SO4 solutions, respectively, to study the performance of ordinary concrete resistance to sulfate freeze–thaw cycle. The specimens underwent visual inspection, and mass losses and relative dynamic elastic modulus (RDEM) were measured regularly. Scanning electron microscope observation and X-ray diffraction analysis were conducted on partial specimens after the freeze–thaw cycle experiment. Research results show that due to the coupling effects of freeze–thaw cycle and sulfate corrosion, freeze–thaw cycles of concrete in Na2SO4 solution caused more damages than in tap water. Higher Na2SO4 concentration produced severe damages. Concrete with different w/c ratios exhibit different sulfate freeze–thaw cycle resistances, and concrete with lower w/c ratio usually produces stronger resistance. RDEM loss is considered the control index to determine concrete failure. The corrosion products in Na2SO4 solution freeze–thaw cycle are mainly ettringite and gypsum. With the increase in Na2SO4 concentration, ettringite formation gradually decreases and gypsum formation gradually increases.

Applying the three R’s: Reduce, reuse, and recycle in the chemical industry

ABSTRACTPollution prevention (P2) assessment was conducted by applying the three R’s, reduce, reuse, and recycle, in a chemical industry for the purpose of reducing the amount of wastewater generated, reusing paint wastewater in the manufacture of cement bricks, recycling cooling water, and improving water usage efficiency. The results of this study showed that the annual wastewater flow generated from the paint manufacturing can be reduced from 1,100 m3 to 488.4 m3 (44.4% reduction) when a high-pressure hose is used. Two mixtures were prepared. The first mixture (A) contains cement, coarse aggregate, fine aggregate, Addicrete BVF, and clean water. The second mixture (B) contains the same components used in the first mixture, except that paint wastewater was used instead of the clean water. The prepared samples were tested for water absorption, toxicity, reactivity, compressive strength, ignitability, and corrosion. The tests results indicated that using paint wastewater in the manufacture of the cement bricks improved the mechanical properties of the bricks. The toxicity test results showed that the metals concentration in the bricks did not exceed the U.S. EPA limits. This company achieved the goal of zero liquid discharge (ZLD), especially after recycling 2,800 m3 of cooling water. The total annual saving could reach $42,570 with a payback period of 41 days.Implications: This research focused on improving the water usage efficiency, reducing the quantity of wastewater generated, and potentially reusing wastewater in the manufacture of cement bricks. Reusing paint wastewater in the manufacture of the bricks prevents the hazardous pollutants in the wastewater (calcium carbonate, styrene acrylic resins, colored pigments, and titanium dioxide) from entering and polluting the surface water and the environment. We think that this paper will help to find the most efficient and cost-effective way to manage paint wastewater and conserve fresh water resources. We also believe that this paper provides a rich agenda for future research in water conservation and industrial wastewater reuse subjects.

PENGGUNAAN TERAK NIKEL SEBAGAI AGREGAT DALAM CAMPURAN BETON

Nickel slag is one kind of nickel ore smelting waste after the combustion process. Production of nickel slag PT. Antam Pomalaa Kolaka Southeast Sulawesi province during the period 2011-2012 period approximately 1 million tons of slag / year, with a nickel content in ore processing of nickel is between 1.80% to 2.00%. Visually, the physical form of this nickel slag aggregate resembles. Research on the use of nickel slag as an aggregate in concrete mixture is carried out using a cylindrical specimen with a diameter of 15 cm and 30 cm high by 48 pieces were tested at 28 days with some variations in the mix. Variation 01, 100% natural aggregate, variation 02, nickel slag as coarse aggregate, variation 03, nickel slag as fine aggregate, and variation 04, nickel slag as coarse aggregate and fine aggregate. Aggregate gradation in the mixture is set and is designed so that it meets the specifications gradation mix for maximum aggregate size of 40 mm. The composition of the concrete mixture used is a mixture of concrete with the ratio of cement : fine aggegate : coarse aggregate is 1: 2: 3 in a weight ratio with cement water ratio (fas) is set at 0.5. The results showed that when compared with the use of natural agregate, terak nickel is used only as a coarse agregate, a fine agregate only and combined agregate coarse and fine agregates resulting slump values ??fell 39.47%, an increase of 55.26%, and an increase of 34.21%. As a coarse agregate, terak nickel increases the compressive strength, modulus of elasticity and splitting tensile strenght, respectively for 42.27%, 19.37% and 23.46%. As fine agregate, nickel terak resulting value of compressive strength, modulus of elasticity and tensile strength divided down respectively by 16.75%, 6.70% and 24.58%. As a combination of coarse and fine agregate, terak nickel increases the compressive strength, modulus of elasticity and splitting tensile strenght, respectively for 10.31%, 9.26% and 6.70%.

Analysis of the main factors influencing the permeability-reducing effect of cement infiltration in a river sediment matrix

This research discusses the main factors effecting the permeability reduction due to cement infiltration or top soil masking when cement infiltrates in a river sediment matrix. This is relevant to the migration of pollutants to the groundwater through surface water infiltration, which is an important and urgent problem to resolve. A series of indoor infiltration simulations were performed to measure the infiltration reduction when the cement infiltrate in a selected soil matrix under different conditions (e.g. dry density, postponing time and waterhead, etc.). The infiltration in the cement-treated samples was compared with a reference infiltration with no cement masking or infiltrating. It was found that the infiltration rates of the cement-treated soils were consistently lower than the control sample, indicating an infiltration reduction due to cement infiltration. The average reduction ranged 3.59-44.33% depending on different processing methods. In this paper, some main factors affecting the permeability-reducing effect of cement infiltration in a river sediment matrix, such as the soil texture, dry density, postponing time of water supply, initial waterhead, and cement addition quantity, are discussed, and theories regarding cement infiltration mechanisms are presented.

UCS Properties of Superfine Cement–Grouted Sand

This research focused on the strength characteristics of superfine cement–grouted sand with various gradations and relative densities. At first, grout properties of superfine cement suspensions were studied. The sedimentation and the setting time increased but the viscosity decreased as the water–cement (W/C) ratio increased. Additionally, the groutability of superfine cement suspensions with different W/C ratios into various graded sand specimens having different relative densities was tried. The groutability of suspensions especially into the fine sand specimens was successful with certain W/C ratios and increased as the W/C ratio increased but decreased as the relative density increased. Grouted sand samples remained in tanks filled with water at a temperature of 20°C until testing time and subjected to unconfined compressive strength (UCS) tests at different time intervals. The UCS of grouted sand specimens decreased as the W/C ratio increased, but it increased as the relative density increased. The UCS of grouted fine sand was greater than that of medium sand. Furthermore, the UCS of grouted samples increased with time.

The application of ultra-fine fly ash in the seal coating for the wall of underground coal mine

To meet the particular safety requirements for underground coal mining, this paper proposes is going to investigate the capability of ultra-fine fly ash (UFA) with styrene-acrylic emulsion to improve safety for underground mine workers. After studying on the influence of different percentages of UFA on the comprehensive property of seal coating, the optimal amount of UFA is determined as 60%. The water absorption of the seal coating after 7d is 5.0%. Its original tensile strength is 3.09MPa. The elongation at break is 80%, and the bonding strength is 0.72MPa (7d) and 1.08MPa (14d), up to the level II standard of GB/T23445-2009 polymer cement water proof coating. The flame retardant property and antistatic property is up to the safety standard for gas-sealing materials of underground coal mine of MT113-1995. Scanning electron microscopy and air tightness tests show that this material has a compact pore structure with good air tightness, and can be used as gas seal coating for underground coal mine.

Pembuatan Beton dengan Campuran Limbah Plastik dan Karakterisasinya

<span>Research on concrete containing plastic waste as an alternative polymer material has been <span>conducted.It studied the concrete characteristic through compressive strength, impact testing, <span>thermal conductivity, and density testing. Plastic waste used for concrete manufacture was <span>black because it is strong but light. The goal of this research is to determine the characteristics <span>value of concrete with and without plastic waste mixing. Concrete was mixed with the ratio of <span>1cement: 2 sands: 3 gravel and cement water factor of 0.5. The addition of plastic waste were <span>0%, 2%, 4%, 6%, 8%, 10% of cement mass.Specimens used was (15x15x15) cm cube with <span>sides for compressive strength testing, (8x2x2) cm a block with the size of for impact testing, a<br /><span>cylinder with a diameter of 4cm and thickness respectively 0.2 cm and 0.4 cm for thermal <span>conductivity testing, and a sides (15 x 15 x 15)cm cube with for density testing. The diameter <span>of plastic waste was 0.1 to 0.8 cm. The test was performed at 28 days of concrete age. The <span>result showed that the addition of 4% of plastic waste recorded the best compressive strength, <span>impact testing, and thermal conductivity. In this research, the density was of the range (16 ± 6)<br /><span>x 10<span>2 <span>kg / m³up to(22 ± 4) x 10<span>2 <span>kg / m³, compressive strength(21.8 ± 0.2) x 10<span>6 <span>N / m² of the <span>range (16 ± 0.1) x 10<span>6 <span>N / m²to(21.8 ± 0.2) x 10<span>6 <span>N / m², impact (8.7 ± 0.3)x 10<span>-1<span>Joule to the <span>range (3.5 ± 0.3)x 10<span>-1<span>Joules up to (8.7 ± 0.3)x 10<span>-1<span>Joule and thermal conductivity (6.0 ± 0.5) x <span>10 <span>-5 <span>kcal / ms °C was (1.17 ± 0.5) x 10<span>-5 <span>kcal / ms °C to (6.0 ± 0.5) x 10 <span>-5 <span>kcal / ms °C.</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

Assessment of Bahariya Hematite-barite Ore as a Heavy Weight Concrete Mix for Subsea Pipeline Cladding

This study deals with a substitute of high density aggregates used for offshore pipeline coating, the hematite-barite ore mined and produced by Steel Manufacture Company and not used in steel manufacture due to containing barite ore and low iron content. Heavy aggregates of iron ore were imported by petroleum companies in Egypt, for utilization as a major constituent of concrete mix used for coating of offshore petroleum pipelines as a heavy coat for pipeline stability on sea bed and mechanical protection against anchor damages. The hematite-barite heavy aggregates form the main constituents 75% of the concrete mix, with sea water cements and specific water-cement ratio desired to achieve required compressive strength, water absorption and dry density. The laboratory and field tests conducted for the hematite-barite aggregate to ensure that the physical, chemical and mechanical properties complying with coating specification and standards. The hematite-barite heavy aggregate have 3.9-4.2 g/cm³ specific gravity, well graded hematite-barite aggregate, chemically free from detrimental matter. Heavy concrete mix composed from hematite-barite aggregate, sea water cement and fresh water mixed together to produces a concrete mix of 180-185 pcf (2880-2964 kg/m³), minimum dry density and compressive strength varying from 40-47 N/mm² (400-470 kg/cm²), which satisfied the standard specification of submarine pipeline coating.

Influence of mix parameters on pore properties and modulus of pervious concrete: an application of ultrasonic pulse velocity

The major objective of this study was to understand the influence of mix parameters on pore properties and modulus of control and silica fume (SF) modified pervious concrete mixtures with an application of ultrasonic pulse velocity (UPV) technique in defining the structural and hydrological properties. A total of twenty-four different pervious concrete mixtures were prepared encompassing three aggregate gradations with four aggregate sizes, and two levels each of water-to-cement (WC) and cement-to-aggregate (CA) ratios. Additionally, 5 % SF was used as partial replacement for cement to produce twelve SF modified pervious concrete mixes. It was found that permeability mainly depends on mix variables such as WC and CA ratios, and gradations since these factors control the interconnected pore structure of the pervious concrete mixes. Based on the measured mix properties, permeability predictive equation was developed, which followed Weibull distribution, and was mathematical robust with very good statistical goodness of fit measures (R adj 2 > 0.80; S e/S y = 0.432). The equation was rational indicative of the fact that porosity alone might not always be significant in defining permeability of the pervious concrete. UPV test technique employing a set of 55 kHz transducers was used to determine dynamic modulus of elasticity (E d) of all mixes, which yielded UPV in the range of 2750–3400 m/s, and E d in the range of 11–19 GPa. The findings were encouraging in that the estimated moduli using UPV were rational, which was also testimonial of the fact that this technique can be confidently used in future in the periodic evaluation of in-service pervious concrete pavements without having to retrieve field cores.

The effect of controlled permeable formwork liner on the mechanical properties of concrete

Controlled permeable formwork (CPF) liner was developed primarily to improve the surface quality of concrete and thereby its durability. CPF liner allows air and water to escape from the surface adjacent to the formwork. This paper reports an experimental study carried out to investigate the influence of CPF liner on the strength and certain mechanical properties of concrete with three different water–cement (w–c) ratios. The specimens were prepared against CPF liner and impermeable steel formwork (IMF) and tested at various ages starting from 7 to 365 days. Various tests were conducted to assess surface quality; compressive, split tensile and flexural strengths, rebound hammer and abrasion resistance of concrete. The results indicate that CPF concrete performed better than IMF concrete in all aspects. The present investigation reveals that the use of CPF liner has significantly improved the tensile strength (say, 20 %) of concrete and the abrasion resistance has been enhanced to a remarkable level (50–80 %). Further, the surface quality is very essential to assess the cube strength of concrete and the existing testing method slightly underestimates the cube strength.

STRENGTH IMPROVEMENT CHARACTERISTIC OF CEMENT-SOLIDIFIED DREDGED MARINE CLAY WITH RELATION TO WATER-CEMENT RATIO

Dredged marine sediments were retrieved from a maintenance dredge site for examination on the solidification efficacy. The high plasticity clay (CH) sample had low shear strength and high compressibility, making it unacceptable as a geomaterial for construction purposes. Due to its poor engineering properties, the material was destined for disposal offshore: incurring cost, time as well as contamination risks along the transportation route. With solidification, the soil could be improved for potential reuse in reclamation works, for instance. The laboratory investigation involved admixing ordinary Portland cement with the soil at different water-cement (WC) ratios, ranging from 1.5 to 3.5. Left to mature in a confined, damp environment for periods up to 56 days, the solidified specimens were subjected to the unconfined compression test. The measurements were conducted at predetermined intervals of 3, 7, 14, 28 and 56 days. Duplicate specimens were tested using the unconfined compression apparatus in accordance with BS1377 (1990). The unconfined compressive strength (qu) and Young's modulus (EP) were derived from the stress-strain plots. Both the strength and stiffness were found to increase with lower WC ratio and prolonged maturing, where the solidified soil transformed from a soft, weak material to that of a hard, strong one. The strength improvement was as high as 2.5 times that of the 3-day old specimens, while the stiffness increased by 4 times for the large strain range, as derived from the compression tests. Expediency of solidifying the soil with cement was further examined by correlating the strength, stiffness and deformation with WC as well as rest period.

Properties of Cement Paste with Incorporated Sodium Silicate

Sodium silicate, usually known as water glass, is researched as material that can potentially find use in composition of cement based matrix in order to improve its porous structure and related physical parameters. The water glass is applied in cement paste mixture in an amount of 5, 10, 15, and 20 mass% of cement. The water dosage is experimentally accessed in order to attain the same workability of particular mixtures. For the applied water glass and cement, the particle size distribution is measured on laser diffraction principle. Pozzolanic activity of water glass is investigated using modified Chapelle test. The particular studied cement pastes are cured 28 days in water and characterized by basic physical and mechanical properties, whereas the results of mechanical resistivity are supported by pore size distribution data accessed by mercury intrusion porosimetry. Althought the particles of applied water glass are coarser than that of cement and did not exhibit pozzolanic activity, their application partially tightened the porous structure of hydrated products and thus contributed to the mechanical strength by means of filler effect. This makes good prerequisites for future research that will be focused on a development of new types of cement-based composites with incorporated sodium silicate used as an modifying admixture.

175 Mix Ratio Optimization of Cemented Coal Gangue Backfill (CGB) Based on Response Surface Method

Central composite design (CCD) experiments were performed to investigate the effect of cement content, fine gangue rate and water reducer content on the rheological properties of fresh cemented coal gangue backfill (CGB) and the compressive strength of hardened slurry. The parameter of mixture proportion was optimized by Multi-criteria optimization analysis. The results show that the fresh CGB rheological property conforms to Bingham model, the yield stress of fresh slurry is influenced by the interaction of the three factors, and the plastic viscosity increases with cement content, fine gangue rate and water reducer content. The value of 28 days uniaxial compressive strength (UCS28) is proportional to cement content and water reducer content, while it is inversely proportional to fine gangue rate. The overall satisfaction of slurry rises significantly with the increase of water reducer content. However, it increases firstly and then decreases with the increase of cement content and fine gangue rate, and reaches a maximum at cement content of 210 kg/m3 and fine gangue rate of 40%. The developed design method can provide scientific reference to reduce the accumulation of waste residues.

Rubberized Concrete Durability Against Abrasion

Durability performance of rubberized concrete against abrasion is presented in this paper. Surface depth loss was measured when abrasion load was constantly applied on concrete surface at each 500 interval rotation. Specimen with water-to cement ratio of 0.50 and 0.35 was prepared and tested at 28 days of curing age. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against wear when added with crumb rubber. Results showed that crumb rubber shows good potential in providing abrasion resistance to concrete mix. However, in the case of rubberized concrete with silica fume, abrasion resistance was found to be slightly decreased with compressive strength more than 50N/mm 2 due to the lack of low elastic modulus of CR particles to accommodate with denser cement matrix.

Impact of Some Ecological Factors on Fecal Contamination of Drinking Water by Diarrheagenic Antibiotic-Resistant Escherichia coli in Zagazig City, Egypt.

Fecal contamination of drinking water is a major health problem which accounts for many cases of diarrhea mainly in infants and foreigners. This contamination is a complex interaction of many parameters. Antibiotic resistance among bacterial isolates complicates the problem. The study was done to identify fecal contamination of drinking water by Diarrheagenic Antibiotic-Resistant Escherichia coli in Zagazig city and to trace reasons for such contamination, three hundred potable water samples were investigated for E. coli existence. Locations of E. coli positive samples were investigated in relation to population density, water source, and type of water pipe. Sixteen E. coli strains were isolated. Antibiotic sensitivity was done and enterotoxigenic, enteropathogenic, and enterohaemorrhagic virulence genes were investigated by PCR. Probability of fecal contamination correlated with higher population density, with increased distance from Zagazig water plant, and with asbestos cement water pipes. Resistance to at least one antimicrobial drug was found in all isolates. Virulence genes were detected in a rate of 26.27%, 13.13%, 20%, 6.67%, and 33.33% for LT, ST, stx1, stx2, and eae genes, respectively. This relatively high frequency of fecal contamination points towards the high risk of developing diarrhea by antibiotic resistant DEC in low socioeconomic communities particularly with old fashion distribution systems.

Field study on non-invasive and non-destructive condition assessment for asbestos cement pipelines by time-domain fluid transient analysis

Asbestos cement pipelines constitute a significant portion of the potable and waste water systems in many countries in the world, including Australia. Most of the asbestos cement pipes in the developed countries were installed before 1980, and many utilities are observing that the breakage rate is increasing with the ageing of the pipe. Condition assessment for asbestos cement pipes is of important necessity for prioritising rehabilitation and preventing catastrophic pipe failure; however, few techniques are available for direct assessment of the condition of asbestos cement pipes and most of them are localised and destructive. This article outlines a pilot field study of the non-invasive and non-destructive condition assessment of asbestos cement pipelines using fluid transient pressure waves. Fluid transient analysis previously conducted by the authors for metallic pipelines is further developed and adapted to asbestos cement pipes for the detection of localised defects. A new sub-sectional condition assessment technique is proposed for determining the effective wall thicknesses of asbestos cement sub-sections within a section of pipe bounded by two measurement points. A field trial is conducted in Australia on an asbestos cement water main (which has class changes with varying wall thicknesses) to verify the proposed techniques. The wave speeds, lengths and wall thicknesses of sub-sections in different classes are determined and the results are consistent with the information in the design drawings provided by the water utility. This field study, for the first time, verifies that controlled fluid transient waves can be used as a tool for non-invasive and non-destructive condition assessment of asbestos cement pipelines.

Uranium Dissolution in Hyperalkaline TMA-OH Solutions: Preliminary Results

Leaching experiments were performed with depleted UO2 powders in tetramethylammonium solutions (TMA-OH) at pH 13.5 and 12.5, and at different UO2 surface area to volume of solution (SA/V) ratio's to determine the solubility and the dissolution kinetics of UO2 at high pH in absence of cations dominating cementitious waters (Ca,Na, K).The solubility of UO2 increased from pH 12.5 to 13.5 and by increasing the SA/V ratio up to 100 m-1. However, no known U secondary-phases were predicted by geochemical calculations to control the measured U-concentrations. A two-step dissolution process was put forward: 1-a fast initial rate, surface controlled and hydroxo promoted and 2-a sorption process at low SA/V ratio or a continuous residual dissolution process at high SA/V ratio.

The Uses of The Al-Faidiyah Formation Oligocene-Miocene in The Drilling Mud Fluids (Bentonite) at Umm Ar Razam, North-East Libya

The lower member (Faidia Clay) of the Oligocene-Miocene Al Faidiyah Formation at Umm Ar Razam Quarry, northeast Libya has been investigated for its potential as a chemical additive (bentonite) in drilling oil wells. The thickness in outcrop of the examined clay unit is variable but information from the subsurface indicates a maximum thickness of about 25 m. Normally, these clay deposits have a dark green color that becomes brown when weathered. When wet, the clay forms a very plastic sticky mass with soap-like textures. A number of mineralogical, chemical, and physicochemical laboratory analyses using X-ray diffraction (XRD), scanning electron microscopy (SEM-SE & SEM-BSE), X-ray fluorescence (XRF), ion exchange capacity (CEC) and surface area have been made in order to characterize the grade and quality of the examined clays. The overall results show that montmorillonite represents the highest percentage (46 %), minor kaolinite (36 %), and trace chlorite (4 %). Other minerals of heterogeneous mixtures of non-clay minerals such as fine quartz grains, calcite, dolomite, gypsum, K-feldspar, ilmenite, anatase, and hematite are also recognized. The presence of a heterogeneous mixture of non-clay minerals reduces the rheological and physical properties as well as detracts from the commercial performance of the Faidia clay. The unprocessed clay and clay after treatment with the addition of up to 6 % of Na2CO3, did not achieve a swelling volume comparable with standard bentonite. The Faidia Limestone Member (the upper part of the Al Faidiyah Formation) is characterized by very high purity in Al Fatayah Quarry. It is extensively used for concrete aggregates, road tiles, blocks, paints, carpets, the cement industry, papers, pharmaceuticals, water treatment, agriculture, and plastics. The equivalent member in Umm Ar Razam Quarry has a lower grade due to the presence of other carbonates (dolomite) and non-carbonates such as quartz, clay, and glauconite minerals. Fossil contents and lithological nature indicate that this is a typical shelf environment.

Laboratory study on cement admixed marine silt bricks

ABSTRACTFor the purpose of efficient utilization of sediments dredged from harbor, a new method was proposed in this study. Marine silt bricks were made by mixing sediments with cement and gypsum, placing it in a cubic mold with 240 mm in length, 115 mm in width, and 53 mm in height, and curing for certain days. To investigate the effects of cement and initial water content of soil on the mechanical behavior of marine silt bricks, unconfined compressive and flexural strength tests were carried out. Given the same curing time and cement content, the higher the initial water content, the lower the compressive and flexural strength. After 60 days of curing, the compressive strength of marine silt bricks with cement content = 20% and water content = LL (liquid limit) reached approximately 5 MPa. The flexural strength was relatively low. The flexural strength of marine silt bricks with 20% cement and water content = LL was around 1.5 MPa. The compressive and flexural strength decreased with the increase of water/cement ratio. As for the curing time, longer curing time had a positive impact on the compressive strength. The ratio of flexural to compressive strength varied slightly in the range of 0.4–0.5.

A relationship of mesoscopic pore structure and concrete bending strength

Pore structure characteristics are important to improve the strength of concrete. Modified Image Photoshop Pro-plus method is proposed in the study to effectively classify the pore structure parameters. To assess bending strength through the mesoscopic pore structure based on the changing water-to-cement ratio, 10 samples with different water-to-cement ratio were obtained by changing water volume or cement content and Modified Image Photoshop Pro-plus was used to extract pore parameters. A better correlation between bending strength and pore parameters, including average pore diameter and spacing factor with different water-to-cement ratio, is obtained. The relationship of total porosity and bending strength can be linearly described as cement content change and water volume keep constant. Changing water-to-cement ratio obviously varies pore structure parameters' value accordingly.